EPA-AA-TEB-91-01
            USER'S GUIDE
                 to
              MOBILE4.1
(MOBILE SOURCE EMISSION FACTOR MODEL)
              JULY 1991
 U.S.  ENVIRONMENTAL  PROTECTION AGENCY
     OFFICE OF AIR AND RADIATION
       OFFICE  OF  MOBILE  SOURCES
 EMISSION CONTROL TECHNOLOGY DIVISION
      TEST AND EVALUATION BRANCH
          2565 PLYMOUTH  ROAD
      ANN ARBOR,  MICHIGAN  48105

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                                   EPA-AA-TEB-91-01
            USER'S GUIDE
                 to
              MOBILE4.1
(MOBILE SOURCE EMISSION FACTOR MODEL)
              JULY 1991
U.S. ENVIRONMENTAL  PROTECTION AGENCY
     OFFICE OF AIR AND RADIATION
      OFFICE  OF MOBILE  SOURCES
EMISSION  CONTROL  TECHNOLOGY  DIVISION
     TEST AND EVALUATION  BRANCH
          2565 PLYMOUTH  ROAD
     ANN  ARBOR, MICHIGAN   48105

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                            DISCLAIMER
     EPA  is  not  responsible  for  the  accuracy  of  any  MOBILE4.1
diskettes or tapes that  were received from sources other  than  EPA
or the  National  Technical Information  Service  (NTIS),  or  for  the
accuracy of any  draft  MOBILE4.1 diskettes  or  tapes that  may  have
been  released  prior  to  release  of  the  final MOBILE4.1  program.
Further, EPA is not responsible for the accuracy  of  MOBILE4.1  when
modified by the user without consultation with EPA.


     Mention of  specific  products,  product  or corporate  names,  or
trademarks in  no way constitutes  endorsement  of same  by the  U.S.
Government or by the Environmental Protection Agency.
                               -11-

                                                            07/91

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                             ABSTRACT
     This document is the  USER'S  GUIDE to MOBILE4.1.   MOBILE4.1 is
a  computer  program  that  estimates  hydrocarbon   (HC),   carbon
monoxide  (CO),  and oxides of  nitrogen (NOx) emission  factors  for
gasoline-fueled  and  diesel highway  motor  vehicles.   The  program
uses the  calculation  procedures and  emission  factors presented in
Compilation  of  Air  Pollutant  Emission   Factors  -  Volume  II:
Highway  Mobile  Sources (AP-42,  Fourth  Edition,  September  1985;
Supplement A to AP-42 Volume II, January 1991).

     MOBILE4.1  calculates  emission  factors  for  eight  individual
vehicle  types  in two  regions  (low-  and  high-altitude)  of  the
country.    MOBILE4.1    emission   estimates  depend   on   various
conditions such  as ambient temperature,  speed, and mileage accrual
rates.   Many  of the variables  affecting vehicle emissions  can be
specified  by  the user.   MOBILE4.1 will estimate  emission  factors
for  any calendar year  between  1960  and  2020,  inclusive.  The 25
most recent model years are considered to  be  in  operation  in each
calendar year.  MOBILE4.1 supercedes MOBILE4, and is  to  be  used by
the  States  in  the preparation of the highway mobile source portion
of the  1990 base year  emission  inventories required by  the  Clean
Air  Act  Amendments  of  1990.   Compared  to  MOBILE4,  MOBILE4.1
incorporates   several   new  options,   calculating   methodologies,
emission   factor   estimates,   emission  control  regulations,  and
internal program designs.
                               -111-

                                                            07/91

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     Requests  for  copies  of  the  MOBILE4.1  program diskettes  or
tape,  and  for additional  copies of  this User's  Guide should  be
directed to:


           National Technical Information Service (NTIS)
           U. S.  Department of Commerce
           5285 Port Royal Road
           Springfield, Virginia  22161

           Telephone:  (703) 487-4650
     Questions concerning MOBILE4.1  or  this  User's Guide should be
directed to:


           U. S. EPA Motor Vehicle Emission Laboratory
           Office of Mobile Sources
           2565 Plymouth Road
           Ann Arbor,  MI  48105
           Attn:  MOBILE4.1

           Telephone:  (313) 668-4325  (FTS 374-8325)
                       (313) 668-4462  (FTS 374-8462)
                                -iv-

                                                            07/91

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                        TABLE OF CONTENTS
CHAPTER 1:  DESCRIPTION OF MOBILE4.1

1.0  INTRODUCTION	1-1

1.1  TECHNICAL DIFFERENCES FROM MOBILE4 	 1-2

     1.1.1  Impact of Oxygenated Fuels on Emissions
     1.1.2  Options for Composition of Exhaust HC Emission Factors
     1.1.3  Expanded Evaporative Emissions Output
     1.1.4  Twenty-five Model Years in Operation in the Fleet
     1.1.5  Basic Emission Rates for 1981 and Later
              Model Year LDGVs
     1.1.6  Incorporation of Pass/Fail Purge/Pressure Effects
              Evaporative and Running Loss Emission Factors
     1.1.7  Tampering Revisions
     1.1.8  Revisions to Running Loss Emission Factors
     1.1.9  Revisions to Refueling Emission Factors
    1.1.10  Resting Loss Emissions
    l.l.ll  Methane Corrections
    1.1.12  New Carbon Monoxide Emission Standards
    1.1.13  Idle Emission Factor Adjustments Programmed
    1.1.14  By Model Year Optional Output
    1.1.15  Revised Speed Correction Factors
    1.1.16  Revisions to Volatility Impact on Exhaust Emissions
    1.1.17  New Registration Distributions
    1.1.18  Variable Vehicle Counts
    1.1.19  Dieselization Rates for LDVs and LDTs
    1.1.20  I/M Benefits for Decentralized Programs
    1.1.21  Miscellaneous Revisions

1.2  LIST OF ABBREVIATIONS USED IN THIS DOCUMENT	1-16
CHAPTER 2:  MOB I LEA.1  INPUT DATA
2.0   INTRODUCTION  .  .

2.1   CONTROL SECTION
                                                   2-1

                                                   2-4
      2.1.1
      2.1.2
      2.1.3
      2.1.4
      2.1.5
      2.1.6
      2.1.7
PROMPT
IOUNEW
PROJID
TAMFLG
SPDFLG
VMFLAG
MYMRFG
 2.1.8
 2.1.9
2.1.10
2.1.11
2.1.12
2.1.13
2.1.14
NEWFLG
IMFLAG
ALHFLG
ATPFLG
RLFLAG
LOCFLG
TEMFLG
2.1.15  OUTFMT
2.1.16  PRTFLG
2.1.17  IDLFLG
2.1.18  NMHFLG
2.1.19  HCFLAG
2.1.20  Inter-Flag
         Dependencies
                                -v-
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                  TABLE OF CONTENTS (continued)
2.2  ONE-TIME DATA SECTION
      2.2.1     Tampering Rates
      2.2.2     Vehicle Miles Travelled Mix by vehicle type
      2.2.3     Annual Mileage Accumulation Rates and/or
                 Registration Distributions by vehicle type and age
      2.2.4     Basic Emission Rates
      2.2.5     Inspection and Maintenance Programs
      2.2.6     Anti-Tampering Programs
      2.2.7     Refueling Emissions
      2.2.8     Local Area Parameter Record
      2.2.9     Scenario Name
     2.2.10     ASTM Volatility Class
     2.2.11     Minimum and Maximum Ambient Temperature
     2.2.12     "Period l" RVP
     2.2.13     "Period 2" RVP and "Period 2" Start Year
     2.2.14     OXYFLG
     2.2.15     DSFLAG
     2.2.16     By Model Year Inclusion Vector

2.3  SCENARIO SECTION  	 2-48

      2.3.1     Region
      2.3.2     Calendar Year
      2.3.3     Speed
      2.3.4  " "  Ambient Temperature
      2.3.5     Operating Modes
      2.3.6     Vehicle Miles Travelled Mix by vehicle type
      2.3.7     Local Area Parameter Record
      2.3.8     Additional Correction Factors for Light-Duty
                 Gasoline-Fueled Vehicle Types
      2.3.9     Oxygenated Fuels Descriptive Record
     2.3.10     Diesel Sales Fractions
     2.3.11     Trip Length Distribution

2.4  SUMMARY OF MOBILE4.1 INPUT SEQUENCE  	 2-69

2.5  OBTAINING REFERENCED DOCUMENTS  	 2-69


Appendix 2A:  Inspection and Maintenance and Anti-Tampering
             Program Terminology Definitions   	 2A-1
                               -vi-
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                  TABLE OF CONTENTS  (continued)
CHAPTER 3:  MOBILE4.1 OUTPUT

3.0  INTRODUCTION	.  3-1

3.1  PROMPTING MESSAGES 	  3-1

     3.1.1    Control Section Prompts   .	3-2
      3.1.1.1  Title Record Prompt
      3.1.1.2  Remaining Flag Prompts

     3.1.2    One-time Data Section Prompts .  .	3-2
      3.1.2.1  Tampering Rate Prompts
      3.1.2.2  VMT Mix Record Prompt
      3.1.2.3  Annual Mileage Accumulation Rates and/or
                Registration Distributions by Age Prompts
      3.1.2.4  Alternate BER Prompts
      3.1.2.5  I/M Program Parameter Record Prompt
      3.1.2.6  ATP Parameter Record Prompt
      3.1.2.7  VRS Descriptive Record Prompt
      3.1.2.8  LAP Record Prompt

     3.1.3    Scenario Section Data Prompts                     3-7

      3.1.3.1  Scenario Descriptive Record Prompt
      3.1.3.2  LAP Record Prompt
      3.1.3.3  VMT Mix Record Prompt
      3.1.3.4  Additional Light-Duty
                Correction Factor Record Prompt

3.2  DIAGNOSTIC MESSAGES  	 3-10

     3.2.1    Introduction
     3.2.2    Explanation of Messages, Listed by Number

3.3  FORMATTED REPORT OUTPUT   	  3-32

     3.3.1    221-Column Numeric Output
     3.3.2    140-Column Numeric Output
     3.3.3    112-Column Descriptive Output
     3.3.4     80-Column Descriptive Output
     3.3.5    By-Model Year Output
                               -vii-
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                  TABLE OF CONTENTS  (continued)

                                                               Page

CHAPTER 4;  MOBILE4.1 IMPLEMENTATION

4.0  INTRODUCTION	4-1

4 . 1  MOBILE4 . 1 TAPE	4-1

4.2  PROGRAM STORAGE REQUIREMENTS 	 4-2

4.3  PROGRAM EXECUTION TIME	4-2

4.4  DEVIATIONS FROM ANSI FORTRAN STANDARD X3.9-1978  	 4-3

4.5  TYPICAL JOB STRUCTURE	4-3

4.6  INSTALLATION AND EXECUTION OF MOBILE4.1 ON
       PERSONAL COMPUTER SYSTEMS  	  4-5

     4.6.1    Introduction
     4.6.2    Downloading the Mainframe Version of MOBILE4.l to
                an Apple Macintosh or IBM-Style Desktop Computer
     4.6.3    Installing and Executing MOBILE4.1
                on Desktop Computers

4.7  MOBILE4. 1 ON THE NCC SYSTEM  .	4-12

4.8  MOBILE4.1 ON THE MTS SYSTEM	4-12

4.9  PROGRAM UPDATE  INFORMATION   	 4-12


CHAPTER 5:  MOBILE4.1 EXAMPLES

5.0  INTRODUCTION	5-1

5.1  EXAMPLES	5-1

     5.1.1    Output Choices	5-2
     5.1.2    User-Supplied  Registration Distributions and
                Annual Mileage Accumulation Rates by Age  .  .  . 5-35
     5.1.3    Anti-Tampering Program 	 5-40
                               -viii-
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                          List of Tables
Table    	Title and Description	       Page
1.1-1    Non-Reactive Organic Compounds  	   1-4
2.1-1    Flags Controlling Input to and Execution of MOBILE4.1 2-71
2.1-2    Flags Controlling Output of MOBILE4.1   	  2-75
2.2-1    Summary of Alternate BER Records	2-77
2.2-2    Summary of I/M Program Descriptive Input Record .  .  .  2-78
2.2-3    Summary of ATP Descriptive Record	2-80
2.2-4    Summary of Stage II and Onboard VRS
           Descriptive Input Records 	  2-82
2.2-5    Summary of the Local Area Parameter (LAP) Record  .  .  2-83
2.3-1    Summary of the Scenario Record(s)	2-84
2.4-1    Summary of the MOBILE4.1 Input Record Sequence  .  .  . 2-88
4.1-1    MOBILE4.1 Tape Characteristics   	  4-2
5.1-1    Summary Description of  MOBILE4.1 Examples  	  5-1
                                -ix-
                                                             07/91

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                           Chapter 1

                GENERAL DESCRIPTION OF MOBILE4.1
1.0  INTRODUCTI ON

     MOBILE4.1 is an  integrated  set  of FORTRAN routines  for  use
in the  analysis  of the  air  pollution impact  of  gasoline-fueled
and  diesel  highway mobile  sources.   The  program provides  the
user with  a flexible analytical  tool  which can be  applied in a
wide  variety  of  air   quality   planning  functions.   MOBILE4.1
updates  and  supercedes  the  previous   version  of  the  model
(MOBILE4),  and  is  to be used in the preparation of  the  motor
vehicle  portion  of  all base  year   1990  emission  inventories
required  by   the   Clean  Air  Act   Amendments   of   1990  for
non-California areas.   It should also be used to  prepare future
year CO emission inventory projections.

     MOBILE4.1 calculates emission  factors for  gasoline-fueled
light-duty  vehicles (LDVs),  light-duty trucks  (LDTs),  heavy-duty
vehicles (HDVs),  and motorcycles, and  for diesel  LDVs,  LDTs,  and
HDVs.   MOBILE4.1  also   includes  provisions  for  modeling  the
effects of  oxygenated fuels  (gasoline-alcohol  and gasoline-ether
blends) on  exhaust CO emissions,   as described  in section 1.1.1.

     This   chapter  briefly  explains  most  of  the  differences
between MOBILE4.1  and MOBILE4.   Many  revisions  are transparent
to the  user,  in  that  no  input data changes are required and the
physical appearance of the output is  unchanged.  Other revisions
to  the  program provide the  user  with previously unavailable
options  or  require  that additional  input   data  be  provided.
Throughout  Chapters   2  (Input)  and 3  (Output), note  is  made of
changes  that  affect  the preparation  of the  input data   stream
and/or  result in differences in  the output  files.

     Most  of  the revisions  that have been  made  to the emission
factor  model since the release of MOBILE4 will have an impact on
the  emission  factor  estimates  for  any  year.  EPA's  intent in
developing  MOBILE4.1  was to  make any  revisions  and updates  that
would  assist  in making  the  1990 base  year  emission factors,  and
hence  mobile  source  inventories, as  accurate as  was possible.
Due  to time  constraints  and  the  necessity  of  providing an
updated model to the  States for  use  in preparing these base  year
 inventories,  many  of  the   pending  future  requirements  of  the
Clean Air Act Amendments  of  1990 are  not reflected in MOBILE4. l.
 (Revised   carbon  monoxide   emission  standards   for   light-duty
vehicles  and  trucks  are  an  exception,  as  discussed  in section
 1.1.12.)   EPA intends to continue work  on  incorporating the  many
 future  requirements of the CAAA  in another  update  to the model.
                                                          07/91

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                               1-2


     Instructions  on how  to  use  the program  are contained  in
Chapters  2,  3,  and 4  (Implementation).   Chapter 5  (Examples)
contains  listings  of  several  input files  and  the  resulting
program   output,   with   descriptions  of   the  features   being
illustrated.   The  source  code  listing  of  MOBILE4.1  will  be
printed under  separate  cover,  rather  than included  herein,  due
to  its  length.   Of course, copies of  MOBILE4.l  on magnetic tape
or diskette can be used to generate source code listings.

     This User's  Guide  is a  self-contained document,  such that
earlier  versions  of the  User's  Guide  are  not  necessary  for
operating MOBILE4.1.


1.1  TECHNICAL DIFFERENCES FROM MOBILE4

     In addition  to updates that have been made to the emission
factor data base  as a result  of  the considerable  amount  of  new
test data collected since  the development of MOBILE4, there have
been a  number of  changes  to the  methodology  used to  calculate
some  of  the  emission  factors  and  correction  factors.   This
section  does  not  attempt  to  detail every case where  the data
base has  been updated.   The  sections below describe  (1) those
features  that  are  entirely  new to MOBILE4.1,  and thus  have  no
direct corollary  in earlier  versions of the model, and  (2) those
features  that have been  significantly  revised  since  MOBILE4.
The  "new"  features  are  described   in  sections  1.1.1  thorough
1.1.4,  and  the significantly  revised features  are described  in
sections  1.1.5 through 1.1.21.

1.1.1  Impact of Oxygenated Fuels on Emissions

     In using MOBILE4,  those wishing  to  model  the impacts of an
oxygenated  fuel program  on  exhaust  or evaporative emissions were
directed  to  use   the  model  output,  in  conjunction   with  the
"Guidance Document"[1]  for  oxygenated fuel benefit calculations,
to  calculate  the  effects  outside   of  the program.   MOBILE4.l
incorporates   the  ability   to  model  the  direct   impact   of
oxygenated  fuels  on exhaust  carbon  monoxide  (CO)  emissions,  and
the  indirect  impact of  changes in  fuel  volatility (as measured
by  Reid vapor pressure,  or RVP) due  to oxygen content on  exhaust
hydrocarbon (HC),  CO,  and oxides  of nitrogen  (NOx) emissions,
and  on evaporative, refueling,  and  running loss  (section 1.1.8)
HC  emissions.

     Distinct   multiplicative   corrections   for    exhaust   CO
emissions have been developed  for each vehicle  type, model year,
and  fuel  type.   Since straight gasoline  contains  no  oxygen,  the
fuel  types  for which adjustment factors have been developed are
alcohol blends  (gasoline blended with alcohol,  such  as ethanol)
                                                          07/91

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                               1-3


and ether blends  [gasoline  blended with ether compounds,  such as
methyl tertiary butyl ether (MTBE) or ethyl  tertiary butyl ether
(ETBE)].  The  adjustments  are a  function of the  oxygen  content
of the fuel.

     EPA has  decided not to  incorporate the  direct effects  of
oxygenated fuels  on  exhaust  HC  and  NOx emissions  in  MOBILE4.1
for several reasons.  The impact of oxygenated  fuels is greatest
on CO  emissions,  there is  less uncertainty  involved in modeling
these  effects,  and  there  are  fewer  implications  for  other
emission  control  strategies  of  small  errors  here  than  in  the
case of  exhaust HC  or  NOx.   As part  of the ongoing regulatory
negotiation process  on reformulated gasolines,  EPA  continues to
develop and to  be provided  with data on the exhaust HC  and  NOx
effects  of oxygenated  fuels.  Consideration  will  be given  to
including such effects in a subsequent model update.*

     The  various  components  of  evaporative HC  emissions  (hot
soak,  diurnal,  refueling,   running loss) are  adjusted for  fuel
oxygen  content on  the basis  of   the  volatility  effect   of  the
oxygenate  on  the  fuel,  accounting for commingling  effects  and
the possible  presence of RVP waivers  for oxygenated blends.   An
example of commingling  is  the volatility increase of the fuel in
a  vehicle's   fuel  tank  (over what  would  be  predicted   from  a
purely  linear  relationship)  when  a  vehicle  containing  some
gasoline in the tank is refueled with  a gasoline/alcohol blend.
These  adjustments  affect  all  gasoline-fueled  vehicle types  in
all model years.

     The  user  who  wishes  to model  the  effects of oxygenated
fuels  must  supply five new pieces of  input data:   the fraction
of fuel sold  in the  area being modeled  that  is  ether blends,  the
fraction  of   fuel  sold  in  the  area  that is  alcohol blends,  the
average  oxygen content (fraction  by  weight) of  the ether blend
fuels,  the average  oxygen  content of   the  alcohol  blend fuels,
and  whether  or not  an RVP  waiver for  alcohol-based oxygenated
fuels  is  in  effect.   There are maximum  oxygen contents for which
emission  benefits  will  be  calculated  by  MOBILE4.1   (3.5 wgt
percent  for  alcohol  blends  and  2.7  wgt  percent  for  ether
blends), since  these  are the  maximum  oxygen contents of commonly
marketed blended fuels.
 *  A  few users should be alert  to  the  fact that  the  absence of
 an  estimate of the direct  effect  of  oxygenated fuels  on exhaust
 HC  and  NOx emissions  is a  shortcoming  of MOBILE4.1 that  may be
 of  significance in  the preparation  of typical  1990  summer day
 ozone  precursor  emission  inventories   for  ozone nonattainment
 areas  with substantial  oxygenated  fuel  market share  in  the
 summer  (e.g.,  the  Chicago CMSA).  Such  areas  should  contact EPA
 to  discuss how to  proceed with  inventory preparation in light of
 this  shortcoming.

                                                          07/91

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                               1-4
     The input changes required for this  feature  of  MOBILE4.1 to
be  used  are discussed  in  detail  in  section 2.2.14.   If  the
modeler does  not wish to  include  oxygenated  fuels effects,  no
changes to  the  input  are required;  as  discussed in  Chapter 2,
the program has  been  designed to assume that no  oxygenated fuel
effects are  to  be  modeled  if  the  required flag  and  associated
input data are missing.

1.1.2  Options for Composition of Exhaust HC Emission Factors

     Past versions  of the emission  factor  model have  provided
the user  with two options  for the calculation of HC  emissions,
either total  HC  (THC)  or non-methane HC  (NMHC).   This selection
is  controlled by  the input flag  NMHFLG (see section  2.1.18).
The only  difference  in  these two  emission  factor  estimates is
that  methane  (CH4)  was  included  in  the  THC emission  factors
and not included in the NMHC emission factors.

     EPA has  determined  that VOC, which consists  of any organic
compounds   that   participate    in   atmospheric   photochemical
reactions, includes all  organic compounds with the  exception of
those listed  in Table 1.1-1:

                           Table 1.1-1

                 Non-Reactive Organic Compounds

               methane
               ethane
               methylene chloride
               1,1,1-trichloroethane (methyl chloroform)
               trichlorotrifluoroethane (CFC-113)
               trichlorofluoromethane (CFC-11)
               dichlorodifluoromethane (CFC-12)
               chlorodifluoromethane (CFC-22)
               trifluoromethane (FC-23)
               dichlorotetrafluoroethane  (CFC-114)
               chloropentafluoroethane (CFC-115)
               dichlorotrifluoroethane (HCFC-123)
               tetrafluoroethane  (HFC-134a)
               dichlorofluoroethane (HCFC-141b)
               chlorodifluoroethane (HCFC-142b)
               2-chloro-l,l,1,2-tetrafluoroethane  (HCFC-124)
               pentafluoroethane  (HFC-125)
               1,1,2,2-tetrafluoroethane  (HFC-134)
               1,1,1-trifluoroethane (HFC-143a)
               1,1-difluoroethane (HFC-152a)
                  and  certain perfluorocarbon compounds
                                                          07/91

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                               1-5


     The compounds listed  in  Table  1-1-1  have been determined to
have negligible  photochemical reactivity, that  is,  they do  not
contribute  significantly  to  ozone  formation.  Of  the  compounds
listed in Table  1.1-1,  methane and  ethane  are present  in  motor
vehicle exhaust  emissions.   States  have  been advised  that  these
compounds should be  excluded  from baseline  emission inventories
to  be  used  for  Reasonable  Further  Progress  determinations.
However, ethane  is to  be  included in  both  EKMA and Airshed  air
quality modeling.

     The emission  factors  for HC which underlie the modeling of
in-use emission  factors are based on measurements  using  a  flame
ionization detector  (FID).  The FID  measurements include methane
and  ethane,  but do  not include  formaldehyde  and  (to  a lesser
extent)   acetaldehyde.     Formaldehyde   and   acetaldehyde   are
reactive  compounds.   To  accomodate  various  intended  uses  for
inventory   preparation  and   air   quality    modeling,   several
adjustments have been made to MOBILE4.1  to  allow  estimation of
highway vehicle emission factors.

     MOBILE4.1  provides  the  user   with  five options   for  the
calculation of  HC  emission factors:   total  hydrocarbons (THC),
non-methane  hydrocarbons   (NMHC),   volatile  organic   compounds
(VOC),  total  organic  gasses  (TOG),  and  non-methane  organic
gasses   (NMOG).    Evaporative  emissions   (hot  soak,   diurnal,
refueling,  running  loss,   and  resting  loss)  do  not  contain
methane,  ethane,  or  aldehydes, although  they  do  contain ethers
and/or  alcohols if  these  compounds  are present   in  the  fuel.
Thus  for  evaporative  emissions,  there  is  no difference  with
these correction factors in the emission  factor  as  a function of
the  composition  option chosen; only  exhaust HC emission factors
are  affected  by the  inclusion or  exclusion  of  methane,  ethane,
and aldehydes.

     The options are accessed through HCFLAG, as in MOBILE4 (see
section 2.1.19).  Each option is  somewhat  different:

     Total  hydrocarbons (THC):  The total  hydrocarbon  emission
factors  from  MOBILE4.1 are  defined  consistently  with THC  in
earlier versions of the model.  These  emission factors  are  based
on  laboratory  test data using the  FID to measure hydrocarbons.
As such, THC emission factors include  methane and  ethane, but do
not account for formaldehyde and about half of the acetaldehyde.

     Non-methane hydrocarbons (NMHC):   The  definition   of  non-
methane hydrocarbon  (NMHC) exhaust emission  factors in MOBILE4.1
is the  same as  that  used in  earlier versions of the model.   The
NMHC  exhaust  emission  factors  are  defined  as  THC (as  defined
above) minus methane emissions.  (As described in section 1.1.11,
the methane offsets  also have been  updated  in MOBILE4.1.)   This
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is calculated in MOBILE4.1 by  subtracting methane emissions from
THC emissions.   All evaporative HC emissions  (hot  soak,  diurnal,
refueling, running loss, and resting  loss)  are composed entirely
of NMHC.

     Volatile organic  compounds  (VOC):   This  option  is new  to
MOBILE4.1,  and  provides  emission   factors   that  exclude  the
designated nonreactive  compounds measured  by  the FID  (methane
and ethane) while  including  two reactive compounds not measured,
or  only  partially  measured,   by  the   FID   (formaldehyde  and
acetaldehyde).   This is  accomplished  by  subtracting methane from
the THC exhaust emission factor,  then  adjusting  the  result  to
exclude the ethane and account  for the aldehydes.

     The  adjustment  factor  is  based  on vehicle  emissions test
data,  and differs  by technology  group  (non-catalyst,  oxidation
catalyst,  three-way  catalyst,  three-way-plus-oxidation catalyst,
diesel)  and  by fuel type   (gasoline,  diesel,  gasoline/alcohol
blends,  and  gasoline/ether  blends).   At  this  time,  the only
correction factor  available is based  on  testing of  gasoline-
fueled  and diesel vehicles;  it  is  also used in  MOBILE4.1  for
gasoline/alcohol   and   gasoline/ether  blends.    EPA   plans   to
develop  specific  correction factors  for these fuel blends  for
inclusion  in a  subsequent  update to the  model.   The  adjustments
are also model-year specific.

     Total   organic   gasses   (TOG):    The   fourth  option  for
hydrocarbon  emission  factors is that  they be  expressed  as TOG.
In  this case,  THC emission factors are  corrected  to  account for
formaldehyde  and  acetaldehyde  emissions.    The   form  of  the
adjustment and  the specificity  (technology groups, model years,
fuel  types)   are  as   described   above,   with  the  calculation
performed  as  (THC emissions  minus  methane)  times  (adjustment
factor,  determined  on  the  basis  of  test  data,  to  convert
non-methane  HC to total  organic  gases),  then adding  back  the
methane  emissions.  Emission  speciation profiles  generally  use
TOG  as the  denominator for the  profile mass  fractions,  so  TOG
output  from  MOBILE4.1  will  be  useful   in  the   development  of
speciated  emission inventories.

     Non-methane   organic   qasses  (NMOG):    The   final   option
available  is to  express the  HC  emission  factors  in  terms  of
NMOG.   This  option  includes  HC  as  measured  by the  FID  in
laboratory tests,  and  accounts   for  aldehydes,   but  does  not
include  methane.    In  other words,  NMOG  is  TOG  without  adding
back the methane emissions.

     It  is worth  noting that  the VOC,  TOG,  and  NMOG emission
factors  calculated  by  MOBILE4.1   are  in  no  way adjusted  for
ozone-forming   reactivity.   Also,  all   of   the  HC  composition
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                              1-7


output  options  calculate  mass  based  on FID-measured  elemental
carbon  emissions  and  a  long-assumed  average  hydrogen/carbon
ratio  for  hydrocarbons  (plus  aldehydes).   Subsequent  revisions
to the  model  may reassess the  use of  this  historical ratio  on
the basis of more recent test data.

     The selection of  the  appropriate  option for estimating "HC"
emissions depends on the use for  which the emission  factors  are
being  calculated.   Additional  information  and  guidance  appears
in  the  revised  edition  of   the  base  year  emission  inventory
preparation guidance.[2]

1.1.3  Expanded Evaporative Emissions Output

     Many  of  the areas  required to  prepare base  year  emission
inventories in response  to the  requirements of the CAAA  of 1990
are  also required to use photochemical grid  modeling (e.g. ,  the
Urban  Airshed Model)  in  attainment  projection  demonstrations.
Such  models  require  that the  emission  inventory be  described
with much finer spatial and  temporal resolution  than  is  required
of  inventories used for simpler models  (e.g.,  Empirical  Kinetic
Modeling  Approach or  "rollback"  models).   Typically,  emissions
from  all sources, including highway vehicles,  must be specified
on  an hourly basis for  each grid  cell, which  generally  is  no
larger than 5 km x 5 km.

     MOBILE4  and  earlier  versions  of  the  model have  generally
been  developed to provide emission  factors  for an  entire area
(national,  state, or  urban  area) on  a daily  basis.  This  was
particularly  true of MOBILE4,  in  which the user was  required  to
supply  as  input  three  temperature  values  including the  daily
minimum  and maximum temperatures,  which are used to  calculate
trip-  and emission-weighted  daily  average temperatures  for  use
in  correcting exhaust,  hot  soak evaporative,  and running loss
emissions.   The  daily  minimum  and  maximum  temperature  also
define  the  diurnal temperature  rise,  which  is  used  in  the
estimation of in-use diurnal evaporative emissions.

     The  temperature   control  flag  TEMFLG  in  MOBILE4 could  be
used  to  override  the  calculation  of trip-  and emission-weighted
average  daily temperatures,   forcing  the input  value of  ambient
temperature to be used to correct exhaust,  hot  soak,  and running
loss  emissions.   This  permitted  the calculation of  exhaust  and
running  loss emission  factors  that  are  specific  to conditions
over  a  shorter   time,  such   as  an  hour.   However,  the  diurnal
component  of  evaporative   HC  emissions   in  MOBILE4  is  only
calculated  as a   function  of the  user  input  minimum and maximum
temperatures,  regardless of  the  value  assigned to  TEMFLG.   In
addition,  all of  the  components  of  evaporative emissions (hot
soaks,  diurnals,  and  crankcase emissions)  were then  combined,
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using data on the  typical  trips per day and miles per day driven
by vehicles  of  different  ages,  to  provided average  fleetwide
evaporative emission factors in units of grams per mile.

     In order  to provide the user of the  model  with information
that can be used to develop hourly  specific  emission factors for
all   emission   components   (exhaust,   evaporative,   refueling,
running loss, and  resting  loss),  a new option has  been  provided
in  the  output.   This  "expanded  evaporative  emission  factor
report" is accessed  through the use  of the  control  flag HCFLAG
(see  section  2.1.19).   Where MOBILE4 provided two options using
HCFLAG, MOBILE4.1 provides three:   (1)  all types  of HC emissions
summed  together  in  a  single  gram-per-mile  emission  factor,
(2) separate  listing of exhaust  HC, evaporative (hot  soak and
diurnal)  HC,  refueling  loss  HC,  resting loss  HC,  and running
loss HC,  with  both the  combined  total  and  each  component given
in grams  per  mile,  and  (3)  expanded evaporative emission factor
output, which  includes  all of  the  information  listed in (2)  as
well  as another  block  of output per scenario providing detail on
the evaporative  emission breakdown in grams,  as described below.

     If the  expanded evaporative  emission factor  output option
is selected by  the user, an additional block of emission factors
is provided for  each scenario.  For  each gasoline-fueled vehicle
type,  this  output provides  estimates  for hot soak  emissions  in
grams  per trip (trip  end),  diurnal  emissions   (based on  the
diurnal temperature rise  as determined  from the  input minimum
and maximum temperatures)  in grams  per  vehicle per day,  multiple
diurnal   emissions   also   in  grams  per  vehicle  per  day,  and
crankcase emissions  in  grams per  mile.    Refueling emissions are
provided  in grams  per  gallon of dispensed fuel,  and resting loss
emissions  in  grams  per vehicle  per hour.   An  example  of this
output  is included in  Chapter 5 (Examples),  and the output block
is discussed in  Chapter  3  (Outputs).

     As discussed  in the User's Guide to MOBILE4,[3] the diurnal
emission  factors produced  by the  model take into  account four
different types  of daily trip patterns,  each  of  which leads to  a
different type  of diurnal  emission generation:

      (1)   "Single"  or   "full"  diurnal   emissions are what most
      people intuitively understand diurnal emissions  to be; the
     vehicle   is  not   driven  during  the  period  of   rising
      temperatures,  generally between  6-7 AM and  4-5 PM  during
      the  summer,  and  so  the  fuel tank  essentially experiences
      the  entire  rise in  temperature  for  the day.

      (2)   "Multiple" diurnals  refer to  conditions  in  which   a
      vehicle  is not operated  at  all  for two or  more consecutive
      days; after the first day,  the evaporative  control  canister
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                              1-9


     (carbon canister) is largely  loaded,  and  without driving to
     provide  an  opportunity  for  it  to  purge  vapors  to  the
     engine, the  canister  will  not have  as great  a  capacity to
     capture  and  hold  the vapors generated  on the second  or
     subsequent no-driving days.

     (3)  "Partial" diurnals refer to  cases in which the vehicle
     is driven on one  or  more  trips  in a  given day,  but  is  not
     operated for a long  enough  time  within the period of rising
     ambient temperatures to entirely  overcome  diurnal  fuel tank
     heating, and thus generates  some  diurnal emissions.

     (4)  Finally,  some  vehicles are  driven on  so  many  trips so
     frequently over the course  of a  day that purging  of vapors
     generated by  fuel tank heating  entirely  eliminates diurnal
     emissions.

Each  of  these  patterns  was   accounted  for   in  MOBILE4,  and
weighted appropriately on the  basis  of trip pattern  survey data
to provide  the  overall diurnal  emission factor.  MOBILE4.l does
the  same, with the further refinement that the  probability of a
vehicle being driven  in  a given  day  has been made  a  function of
vehicle age.

     The model used in MOBILE4  and MOBILE4.1 to estimate diurnal
emissions as  a  function  of  temperature rise and  fuel volatility
does  not work  well  when based  on   the  very  small  temperature
rises typical of  a single hour.   In  addition, the  trip pattern
survey data  used  to weight  together  the various diurnal emission
events  does not  provide  sufficient   detail  to  similarly weight
the  events   on   an   hourly basis.    The  partial   diurnals  in
particular   are   difficult  to   disassociate   into   hour-by-hour
occurrences,  so  they  are  combined   (by  appropriate  weighting
factors) in  the  "Full  diurnal"  emission factors produced by the
expanded evaporative output option.

     The use of the temperature control option and the expanded
evaporative  emission  factor output described  here together  can
be  used to  estimate  hourly emission  factors.   Exhaust, running
loss, resting loss,  and  hot  soak evaporative  emissions  can be
modeled  directly  as hourly emissions  through  the  use  of TEMFLG
(see section 2.1.14)  and  the  appropriate  hourly  temperatures to
calculate emission factors which  then are multiplied  by. hourly
activity rates.   The  estimation  of hourly  diurnal  and refueling
HC emissions are discussed below.

     The conversion  of MOBILE4.1  daily  diurnal emission factors
to  hourly  emission factors is more  problematic.   Among the the
applicable   considerations   are   that   hourly  emissions   are
sensitive to  (1)  hourly temperatures  (which determine fuel vapor
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                              1-10


density in the vehicle  fuel  tank),  (2) temperature rise over the
course  of  an  hour   (which  determines  vapor   expansion   and
expulsion), and  (3)  the fact  that  near the  end  of the  day the
carbon canister may be approaching its  vapor  capacity,  such  that
incremental additions of vapor  are  more likely to be released to
the atmosphere.

     As  of  this  writing,   EPA  recommends  that  daily  diurnal
emissions   be   calculated   from  the  minimum   and   maximum
temperatures, and that  these emissions be allocated to specific
hours on the  basis  of the fraction of the day's temperature  rise
that occurs within  the given hour.   (For  example, if  the daily
minimum  and  maximum  temperatures  are 60°  and  84 °F  (16°  and
29°C), and the temperatures at 12 noon  and 1  PM are 77° and  80°F
(25°  and  27°C),  then the diurnal emissions  occurring  between 12
noon  and  1  PM are  one-eighth (3F°/24F°) of the  daily  diurnal
emissions.  EPA  will provide  additional guidance  on the subject
of hourly allocation of diurnal emissions as  it is developed.

     Refueling emissions  should also  be  based on  daily  minimum
and maximum  temperatures  in most  cases.   The algorithm  used in
MOBILE4.1 to  calculate  refueling emissions uses  the temperature
of  the  dispensed  fuel (the new fuel  being added  to the vehicle)
and the difference in temperature between  the dispensed fuel and
the residual  fuel (the fuel remaining in the  vehicle  fuel  tank
when  the  refueling occurs), with  each of these  being  estimated
from the minimum and maximum temperatures.

     MOBILE4.1  will  estimate  refueling  emission  factors  using
the  ambient   temperature,  rather than the  minimum and  maximum
temperatures,  if  TEMFLG =  2 (see section 2.1.14).   However, if
this approach is taken, the  temperature used  should be  the daily
or  (preferred)  monthly  average  temperature.   This is  because
underground   tank  temperatures  (and   hence   the  dispensed   fuel
temperature)  do  not  vary as  hourly  temperatures  vary over the
course of a day.

      In  estimating  refueling emissions on an hourly basis,  EPA
recommends that  refueling emission factors  on  a  daily basis for
the  day of  interest be  calculated,   and  allocated to specific
hours   taking  into   account  the   following:    Emissions   are
proportional  to  fuel sales.   Typical  fuel sales  over  the course
of  a  day would  have both  morning  and  afternoon/early evening
peaks,  with  slower  mid-day sales and very low  sales  between
approximately 10-11  PM and  5-6 AM.   In allocating fuel sales by
hour,  use reasonable judgment  and  document  assumptions  made in
the  emission  inventory submitted  to  EPA.   If  any  hourly   fuel
sales  data  are available for  the area being modeled,  such   data
should  be  accounted for.   A relatively simple, short-term survey
of  refueling  activity at a  small  number of service stations  also
would be adequate to  estimate  relative  sales  by hours.


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                              1-11


1.1.4  Twenty-Five Model Years in Operation in the Fleet

     In  MOBILE4  and  earlier  versions  of  the  emission  factor
model,  a 20-model-year  "window"  of vehicles  was considered  to
comprise  the  in-use  fleet  in  any  given  calendar  year.   For
example,  if  the  calendar  year  of evaluation  was  1990,  then
vehicles  ranging  in  age from one (model year  1990) to  20 (model
year 1971) were assumed to make up  the  fleet.  Any vehicles over
20 years  of  age were grouped together with 20-year-old vehicles;
thus the registration fraction of age 20 vehicles  is  higher than
that of  age  19 vehicles,  and all vehicles more than 20 years old
were modeled as being 20 years old.

     The  registration distributions  by age  had  20  values  for
each  vehicle  type,  corresponding to ages 1, 2,  3,   ...  ,  20+.
Similarly,   annual   mileage   accumulation  rates  by   age  were
provided  for  vehicles  of ages  1,  2,  ...  ,  20+.   If  the  user
desired   to   input  registration   distributions   and/or  annual
mileage  accumulation  rates  differing  from the national  values
built  into  the code,  then 20  values  were  reguired   for  each
variable,  for  each vehicle type.   (The exception is motorcycles;
while  the arrays  in the  code provide  for up  to 20  values  of
registration   fraction  and  annual  mileage   accumulation  for
motorcycles, only  12 values  for each were  provided in  the code,
with the  12th  values applied to motorcycles of ages 12 and up.)

     These   arrays   have  been  expanded  to  25  model   years  in
MOBILE4.1.   As before, the  relatively  small number  of vehicles
in-use  that  are  older than this upper limit are combined with
the  25-year-old vehicles  in the  age 25+  category.   Also  as  in
MOBILE4,  only  registration  fractions  and  mileage  accumulation
rates  for motorcycles  of ages  1  to  12+  are  actually  used  in
MOBILE4.1,  although  the  array  sizes have been expanded  to  25
values  each  for all  eight vehicle types.

      If  the  user of  the model  wishes  to  use  the  nationwide
average   (default)   values  for   registration  distributions  and
annual  mileage accumulation rates  by age,  then this  change  is
transparent  to  the  user.  However,  when the  user  elects  to
supply  one or both of  these variables  as  input,  the  input must
now  consist  of  25  (rather  than  20)  values for  each variable
being  input   for  each  vehicle  type.   See   section   2.2.3  for
discussion of  the  input changes.

1.1.5   Basic Emission  Rates  for  1981 and Later Model Year LDGVs

      The basic  emission  rates  for  1981  and later  model  year
light-duty gasoline-fueled vehicles and trucks have been updated
in MOBILE4.1 on the basis on  analysis of  emission factor program
testing results  obtained since  the  release  of  MOBILE4.   These
changes  will   affect  all  exhaust  emission   factors  for  all
pollutants for any calendar year  of evaluation after 1981.

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                              1-12


1.1.6  Incorporation of Pass/Fail Purge/Pressure Effects
       on Evaporative and Running Loss Emission Factors

     EPA has  conducted extensive  testing  of in-use vehicles  in
conjunction with the  State of Indiana's centralized  inspection/
maintenance  program  over  the  last   two  years.   This  program
provided the  opportunity to  test  an  unbiased  sample  of  in-use
vehicles at the time  that they were brought in for mandatory I/M
testing.   As  part  of  the  testing  under  this  program,  EPA
conducted   "purge/pressure"   tests  of  participating  vehicles'
evaporative  emission  control  systems.  These  tests  determined
whether  there  were  any  leaks   in   the   vehicles'   fuel  and
evaporative  control  systems  (pressure  test),  and  whether  the
system  was capable of  purging  the  canister  of vapors  (purge
test).   (Tampering  rates  for   evaporative   emission  control
systems  generally  have been  based on  visual  inspections  rather
than functional testing of the components of the system.)

     Data  from these  tests have  been used to  explicitly account
for  the number of  vehicles with significant evaporative control
system  problems,  and  the emissions  impact  of  those  problems.
The  results  of  this  testing  and  analysis   are  reflected  in
revisions  to  the evaporative  (hot soak and  diurnal)  and running
loss  emission rates used  in  MOBILE4.1.  All model  year vehicles
and calendar years  of  evaluation are affected by these changes.

1.1.7   Tampering Revisions

     As  in MOBILE4, there  are nine tampering rate equations used
to  model  the  impact  of  vehicle  tampering  on  the emissions  of
light-duty gasoline-fueled vehicles  and  trucks.  Each  of  the
tampering  rate equations  has  the  form  of a  zero-mile level and  a
deterioration  rate  (representing  the  increase  in the rate  of
that   type  of  tampering   with   accumulated   mileage).    Each
tampering  rate is   combined with an associated  tampering  offset
(increase  in  emissions for vehicles  exhibiting  a given  type of
tampering)  in order to estimate  the  effect of  tampering  on the
modeled emission factors.

     Eight of the  nine  tampering  rate equations can  be supplied
by  the  user  with  adequate  locality-specific   information  (see
section 2.1.4).     (The  ninth category,  "other  misfueling,"  is
derived as the difference between "overall  misfueling" and "fuel
inlet  restrictor disablement."   See section  2.2.1.)

     Three relatively minor  revisions have  been made to  the
tampering-related  calculations  in MOBILE4.1.   In  addition,  the
tampering  rates  themselves  have  been  updated to  reflect  newer
survey data available since  the  release of MOBILE4.   The three
revisions  are  described below.
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                              1-13


     In MOBILE4,  tampering rates  were  defined for  two distinct
LDGV model year groups,  pre-1981  model  years and  1981  and later
model years.   MOBILE4.1  uses three model  year  groups:   pre-1981
model  year,   1981-83  model  years,  and  1984  and  later  model
years.    This  revision   may  affect  the  input data,   since  the
replacement  of  the  tampering  rate  equations  with  locality-
specific data  now  requires three  sets of equations.  See section
2.2.1 for additional details.

     In MOBILE4, only 1981 and later model year LDGVs  and LDGTs
had  a  two-step tampering  rate equation, with  one deterioration
rate applicable to  vehicles with  up to  50,000  accumulated miles
and  a  second  (greater)   rate of increase in tampering applicable
to vehicles  after  50,000 miles.   In MOBILE4.1, tampering rates
for  all model years of LDGVs,  LDGTs,  and HDGVs  exhibit  this
behavior, with the  deterioration  rate above 50K mi  defined  as a
function of the rate applicable up to 50K mi:

(Rate of increase for >   50K mi) =
           [(Rate of increase for <_ 50K mi) * (adjustment)].

There are  different adjustments  for  each of the  nine  tampering
types,  for  each vehicle type (LDGV,  LDGT,  HDGV),  for each model
year group  defined above, and  for I/M  and non-I/M  areas.   The
adjustment  factors  for  the  tampering  deterioration  rates  are
coded in the  model;  only one deterioration rate is  required for
each case  if  alternate  tampering  rate  equations  are provided as
input data.

     Finally,  all  tampering  rates  reach  a  maximum at   130,000
accumulated  miles.   This means  that whatever  rate  of  tampering
is reached at  130,000 mi (by tampering  type,  vehicle type, model
year  group,  and  I/M  or  non-I/M  case)  will  be applied  for all
mileages in excess of 130,000.

1.1.8  Revisions to Running Loss Emission Factors

     Running  loss   emissions,  defined  as  evaporative  emissions
occuring while the vehicle is in  is  being driven, were included
in MOBILE4 for the first time.   The occurrence of  running  loss
emissions  appears  to   be   at  least   in  part   the  result  of
inadequate   evaporative  canister    purging   during    vehicle
operation; when  the canister  reaches saturation and evaporative
emissions  continue to be  generated  as  a  result  of  fuel  tank
temperature  increases,   these  emissions are  released  from the
vehicle  into  the  atmosphere.   Vehicle fuel  system leaks,  and
possibly other sources,  may  also  contribute to the generation of
running loss emissions.

     Running  loss   emissions are  higher  at  higher  temperatures
and  higher  volatilities (as  are other  evaporative emissions),


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                              1-14


and are  higher  at  lower  average speeds  (reflecting the  lesser
canister  purging that  occurs  at low  speeds).   Running  losses
also  are known  to  be  a  function of  trip  length   (duration  in
time,   not  distance  travelled).    The  levels  also  depend  on
vehicle  type, vehicle age (older vehicles  have higher  rates  of
failure  on purge  and  pressure tests; see  section  1.1.6),  and
evaporative control system type.

     The running loss emission  factors  estimated  by MOBILE4 were
based on data obtained during  testing  over  three driving cycles
of low,  moderate,  and high average  speeds  (7.1,  19.6,  and 47.9
mph),   with   the  emissions  representing   each   average  speed
weighted  together  to represent typical urban traffic  patterns.
In MOBILE4.1,  running  loss  emission  factors  are  a  function  of
four  variabl.es:   average  speed,  temperature,  fuel  volatility,
and (as  a user  option)  distribution of average trip lengths.  It
is  important  to note  that  trip  length here   refers  to  trip
duration   (length   of   time   driving),   not  to  total  distance
travelled  in  the   trip.   Each  of   the  variables   now  used  to
estimate  running loss emission  factors  is discussed below.

      In  MOBILE4,  an average urban  area driving  distribution was
used  to  weight  together  the  three  "levels"  of   running  loss
emissions  into   a single  value for  each  gasoline-fueled vehicle
type.    In MOBILE4.1,  the  average  speed specified by  the  user  in
the   input  is  used  to estimate  running  loss  emissions  as  a
function  of speed,  with the same gram  per  minute  (not  gram per
mile) emission  factors applied to  speeds outside  of  the limits
of the test data (under 7.1 mph or over than 47.9 mph).   Average
speeds  of less  than 7.1 mph have the same running  loss emissions
per unit time as  are  associated with an  average  speed  of 7.1
mph,  meaning  that  the  g/mi   emission  factors   continue  to
increase  as speed  decreases  down to the  global minimum  speed  of
2.5 mph.   Similarly, average  speeds greater than  47.9  mph have
the same running loss emissions per unit time as  are associated
with  an average speed  of  47.9 mph,  such that the  g/mi emission
factors  continue to  slowly decrease  as  speed increases  up to the
global maximum speed of 65 mph.

      The  effects of temperature on   running  losses  are handled in
the same manner  as was done  in MOBILE4:   If  TEMFLG =  1  in the
input,   then   a  trip-   and   emission-weighted  temperature  is
calculated and  used   to   correct   running  loss  emissions  to
temperatures  other  than 75°F.   If TEMFLG =  2,  then the value of
ambient  temperature specified by  the user in the Scenario Record
(see  section  2.3)   is  instead  used  as   the  temperature  for
correction of the running loss  emission factors.

      The effects of  fuel volatility  on running  loss  emissions
were  modeled in MOBILE4  for  input  (dispensed fuel) RVP in the
range of  7.0  to  11.7 psi. This  has  been revised in MOBILE4.1,  in


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                              1-15


that the volatility  effect  of  oxygenated fuels is  accounted for
(see  section 1.1.1),  and  that  the minimum  (weathered, or in-
tank) RVP for which  running loss  emission  factors  are calculated
is now 6.5 psi.   The upper limit of 11.7 psi RVP (weathered) for
calculating  running  loss  emission  factors  is  unchanged  from
MOBILE4.

     In  MOBILE4.1 as  in  MOBILE4,  a  ceiling  is  placed on the
increase  in  running  losses  with  increasing  temperature  and
volatility, to avoid unreasonable extrapolation based on limited
data.  Maximum running losses as  a function  of  temperature occur
at  105°F  (41°C),  with  higher  temperatures  resulting  in  no
further increase  in  running losses.  Maximum  running  losses  as a
function  of  volatility  occur  at  11.7 psi  RVP,   which is the
highest volatility fuel for which EPA  has  collected data.    (This
limit, as  most  other minimum/maximum  RVP  limits  cited elsewhere
in this  document, refers to  the weathered in-tank  level.   This
could correspond  to an  input  RVP as  high  as 13 psi  given  high
temperatures  and  resulting  increased  weathering,   although  such
temperature/volatility combinations are not realistic.)

     The  longer   that a  trip lasts, in terms of total  time for
any  single  trip  at a  given  average  speed,  the  more  likely
running  loss  emissions  are  to  be generated.   MOBILE4.1  uses
national average  (default)  trip duration statistics  to estimate
the  fleet  average  running losses.  No changes are  required to
the  model  input   to  have  these default  values  used.   For   areas
having detailed data on the the trip distribution by length, the
user  can  supply  a  trip duration  distribution  to be  used  in
calculating   running  losses.    See   section  2.3.11  for  more
information  on   this  option  and  the  required   form  of  the
additional input  data.

     Separate  running loss  emission   factors are  calculated for
each  gasoline-fueled  vehicle  type   except  motorcycles  (which
represent a very  small fraction of VMT).

1.1.9  Revisions  to  Refueling Emission Factors

     Refueling emissions, also termed  "Stage II"  emissions, are
generated when vehicles are refueled.   (Stage I emissions  are HC
vapor  emissions  displaced to  the  atmosphere from  underground
service  station  gasoline  storage  tanks  when  these  tanks are
refilled.)   Stage  II refueling  emissions  consist  primarily of
displacement  losses, which occur  during vehicle  refueling  when
the  gasoline vapor   filling  the vehicle  fuel  tank  vapor   space
(that space  remaining above whatever  liquid  fuel  remains  in the
tank)  are  displaced  by  incoming  fuel  and  released  to the
atmosphere,  and to  a lesser extent of  spillage losses  (whatever
fuel  is  spilled,  or dripped  from the  dispensing  nozzle,  during
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                              1-16


vehicle  refueling,   which  completely  evaporates).   EPA   has
estimated  that  vehicle refueling  emissions  account for  as  much
as two  percent  of the  overall  HC  emissions  inventory in  urban
areas.

     In MOBILE4,  refueling  emission  factors were  calculated on
the  basis  of nationwide  average  fuel consumption-weighted  (by
region)  values  of  the  variables  used  in  the  equation  for
calculating the  displacement component of  the  emissions.   (For
additional information  on  the  equation and the values used in it
in MOBILE4, see [3] and [4].)  The  impact of  changes  in fuel RVP
were  modeled  indirectly,   on the basis of  the  ASTM Class  for  a
given area.  The  ASTM Class is specified by  a  letter  (A,  B, C,
D,  E),  with  each  letter   associated  with  a voluntary  maximum
limit on gasoline volatility for a given state  or  part of  state
for  each  month.   This  approach  was used as  a  surrogate  for the
user-input  values  of  gasoline  RVP  to  model  the  impacts  of
different  RVP  levels  on  refueling   emissions.    There  was  no
temperature  dependence  of   refueling  emissions  modeled  in
MOBILE4,  although the  model did not  provide refueling emission
factors at temperatures under 40°F.

     Several  revisions  to  the   refueling  emission  calculation
have  been  made in MOBILE4.1 which allow the impacts  of  the RVP
and  temperatures  supplied by  the user to  be modeled directly.
There are-three  variables  in the equation:  RVP of the dispensed
fuel,  the  temperature of  the  dispensed  fuel  (TD),  and  the
difference  in temperature  between  the dispensed  fuel  and the
residual  fuel  that  remains  in the  vehicle  tank  before  the
refueling  event  begins.   In MOBILE4.1, each of these is a direct
function of user  input data.  The  value  of RVP  in the equation
is  that  specified  by the user   as  applying  to  the  year of
evaluation,  the  dispensed  fuel   temperature   is  estimated  as
either  the  average  of  the  minimum  and  maximum temperatures
specified by the  user  (if  TEMFLG =  1)  or  the ambient temperature
specified  by the user (if  TEMFLG =  2),  and the  difference in
temperature is a  function  of dispensed  fuel temperature.[5]

     The  effect  of   these   revisions  is  to  make  the MOBILE4.1
refueling  emission  factors vary  with the  conditions  that are
being   modeled.    To  prevent  unrealistic   values  from  being
calculated,  there  are limits  set on  the calculated  grams per
gallon  displacement  factor.   No  revisions have  been made. to the
spillage  component  of these  emissions,   the algorithm  used to
convert  gram/gallon emission factors  to  grams  per mile,  or to
the  modeling  of  the  effects of vapor  recovery  systems  (onboard
or Stage II) for  the  control of  these emissions.  The net effect
is  that  refueling  emissions,  at  a   given  RVP, will  vary  with
temperature from  a minimum of  1.8  g/gal (winter  conditions) to  a
maximum of approximately 9  g/gal  (extreme summer conditions).
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                              1-17


1.1.10  Resting Loss Emissions

     Resting  loss  emissions  are  another  form of  evaporative  HC
emissions  which  have  not  been  explicitly  accounted  for  in
previous versions  of the emission  factor  model.   Resting losses
can  be  defined   as  those  emissions  resulting   from  vapors
permeating  parts  of  the  evaporative  emission  control  system
(e.g., rubber vapor  routing hoses),  migrating out of  the carbon
canister,  or  evaporating liquid  fuel  leaks.  They  are distinct
in  definition,  although  not in  measurement,  from  both diurnal
emissions  (in that  the  temperature need  not be  increasing for
resting  losses  to  occur)  and  hot  soak  emissions  (which  occur
when  fuel  evaporates  from  the engine and  fuel  line due  to the
heating of the  fuel  and  fuel system that occurs during a trip).
However, they are  not entirely distinct  from these  other  types
of  evaporative  emissions,   in  that   some  of  what   are   now
explicitly labeled resting   losses have previously been included
in hot soak,  diurnal, and running loss emission measurements.

     Resting  losses  are  a function  of two  factors  in MOBILE4.1,
the  temperature and the  type of  carbon  canister  used  in the
vehicle  evaporative  emission control  system.   Like  other  forms
of  evaporative  emissions,  higher temperatures result  in higher
rates  of  resting   losses.    The   two  types   of   canister   are
"open-bottom" and  "closed-bottom."   An open-bottom  canister,  as
the  term implies,  does   not have  an vapor-impermeable bottom,
while a  closed-bottom  canister does.   Resting losses are greater
from  open-bottom  canisters,  which  are  being  phased  out.   EPA
believes that open-bottom canisters will no  longer  be  a part of
the  new-car  fleet  in  the future, but  a  considerable  number  of
such  vehicles exist  in  today's  fleet,  and  will  be  a steadily
decreasing fraction  of the  fleet for some  years  to  come.   The
estimated  fraction of vehicles by  model  year using each of the
two canister types is coded  into the model.

     Typical  resting  loss  emissions  are  on the  order  of  0.08
grams per  hour from vehicles with  closed-bottom  canisters  at  a
temperature of  75°F (24°C).   The separation of  these  emissions
into  a  distinct  category   is more  an  effort  to  provide the
modeler with the greatest possible  accuracy in the allocation of
emissions  by time and location  than it  is an  increase in the
overall  total  of  evaporative  emissions.   As  noted   above,   a
portion  of what  are now termed resting losses were  accounted for
previously in the hot soak, diurnal,  and  running loss emission
factors,  which have been adjusted slightly  downward to account
for  that fact.   However, because resting  losses  occur over all
24  hours of   the day,  there  is a net  increase in non-exhaust HC
emissions  with  the treatment  included  in  MOBILE4.1.    If  the
emission  factors  are  based on  the  daily minimum  and maximum
temperatures, the  resting loss  emission  factors  will reflect the
average  daily losses,  including  the effects  of  lower  nighttime
temperatures.

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                              1-18


1.1.11  Methane Corrections

     In MOBILE4, the difference between total  HC  and non-methane
HC  emission  factors was  calculated through  the use  of  methane
offsets, or the  g/mi  of methane  typically present  in  each test
segment  (bag)  of the FTP.   These offsets  were constant for each
vehicle type and model year.  In  other words,  the methane offset
applicable to  a  given  vehicle and model year did not change as a
function of accumulated mileage or  increased  total  HC emissions,
meaning  that  the fraction of methane included in the exhaust HC
emission factors decreased over time.

     In  MOBILE4.1,  the  methane  offsets  have  been  replaced  by
methane  emission  rate  equations,  similar  to those used for other
exhaust  emissions.   These  equations,  which  are  technology  and
model year specific  for 1981 and later LDGVs, consist of a zero-
mile level (ZML) in grams per mi  (g/mi) and a deterioration rate
(DR)  in g/mi/lOK mi.   Data indicate that  as  total HC emissions
increase, methane emissions also  increase, although  at  a slower
rate; thus,  the fraction  of  total  HC that  is methane decreases
over time.  The  non-methane emission factors  from  MOBILE4.1  are
then  determined by subtracting the appropriate  values  from  the
total HC emission factors,  as before (see section 1.1.2).

1.1.12  New Carbon Monoxide Emission Standards

     The  Clean Air  Act  Amendments  of  1990 (CAAA)  include many
new  requirements for  vehicles,  including  new tailpipe emission
standards  to  be phased  in beginning with  the 1993  model year.
As  previously  noted,  most  of  the  requirements   of  the  CAAA
applicable  to  the  future  have   not  been   incorporated   in
MOBILE4.1.   However,  those  areas  in  nonattainment  with  the
National  Ambient  Air   Quality  Standard   (NAAQS)   for   carbon
monoxide  (CO)  have  been given  a  State  Implementation Plan (SIP)
development schedule that  is considerably shorter  than that  for
ozone nonattainment  areas.   For this reason,  the new CO emission
standards for  light-duty gas  vehicles  (LDGVs)  and trucks  (LDGTs)
have been incorporated  in MOBILE4.1.

     There are two  new  CO emission standards  of interest here:
the  so-called  "Tier  I" tailpipe  standards, which are applicable
at  standard FTP conditions, and the "cold CO" standard, which is
applicable  over the  FTP cycle  at  20°F  (-7°C).   Each  of these
standards  is  phased  in  over  several  model  years,  with each
manufacturer  required  to certify a specified percentage  of  the
model  year's   production  to  the  new standard.   This means that
the overall fleet fraction  certified to the new standard in each
model year of  the phase-in  period is the same.
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                              1-19


     For  LDGVs,   the  Tier  I  CO  standard  is  the  same  as  the
current  standard  (3.4  g/mi),   thus  no  changes  to  the  MOBILE4
basic emission rate  equations  were necessary.  For  LDGTs,  there
are actually two  sets of  Tier  I CO standards,  the certification
standards in §202 of the  revised Clean Air Act (CAA),  and  a set
of intermediate certification  standards which are given  in §207
of the  new  CAA.   All of  this  has been accounted  for  in  the new
BERs for model years 1994  and later in MOBILE4.1.*

     The  cold  CO  standards  represent  the  first  time   that
tailpipe emissions have been controlled  at  conditions other than
those of the FTP.  These  standards (10 g/mi  for   LDGVs,  12 g/mi
for  LDGTs  at 20°F)  are  accounted for in MOBILE4.1  by assuming
that  the necessary  reductions  will   come  from  the  cold-start
(bag 1) portion of the FTP, when CO emissions are  the greatest.

1.1.13  Idle Emission Factor Adjustments Programmed

     The  idle emission  factors  that  were  produced  by  MOBILE4
represent  emissions  at  idle  from engines   in  stabilized  mode
(thoroughly  heated  engine  and catalyst).   Due  to  lack  of idle
data at other temperatures, operating  modes,  and  fuel volatility
levels,  the  same  idle emission  factors were  produced regardless
of  the  conditions specified  by  the  user.    In  response to the
need  for  modeling   idle   emissions  (particularly  CO) at  other
conditions,  primarily  at  cold  temperatures  and  in  cold-start
mode, EPA developed an  algorithm by  which  the  stabilized idle
emission  factors  at  75°F  and  9.0 psi RVP  could  be  adjusted  to
other conditions  outside  of the  model.[6]  While the method was
somewhat  cumbersome,  it  allowed a reasonable  estimate  of idle
emissions at non-standard conditions to be calculated.

     MOBILE4.1  has  been  revised  to   incorporate  a  similar
algorithm.  When  idle emission factors are requested,  they will
be  adjusted  to  the conditions specified in the input data file.
Note  that  this   adjustment is   essentially  the  same  as  that
recommended  for  use  with  MOBILE4;   EPA  still   does not  have
sufficient   idle  emission data  over  a  range   of  operating
conditions to develop idle-specific temperature,  operating mode,
or fuel volatility correction factors.
*   In actuality,  the BERs  for LDT  CO emissions  for  1994  and
later  model years  are no  different  than  those used  for  model
year  1993.   Analysis  of  in-use  vehicle emission  data revealed
that  manufacturers  have already achieved  compliance  with  the
"Tier  I" CO standard  with  fuel-injected  LDTs,  which will  be
fully phased into the new vehicle fleet by 1994.


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                              1-20


1.1.14  By Model Year Optional Output

     For previous  releases  of the mobile  source  emission factor
model,  EPA  later   developed   "by  model  year  versions."   This
version of  MOBILE4 provided an expanded type  of  emission factor
output table  in  which  the emission factor for each  model years'
vehicles,   for  each  vehicle  type,   in  the  calendar  year  of
evaluation was provided.  For  example,  if  the calendar  year was
1990, the  by model year  output  would show  the  emission factors
for model year  (MY) 1990 vehicles  in 1990,  MY 1989  vehicles in
1990,  and  so on through MY 1971  and earlier vehicles  in 1990.
The  appropriate  travel fraction  weightings  were  also  provided,
as well  as the  weighted  contribution of vehicles  of each model
year to the calendar year fleet emission factor.   Such a version
of  the model's  output is  particularly  useful when there  is  a
need to examine  the impact  of a given emission  control  strategy
(e.g.,  enhancement of  an I/M  program)  on vehicles  of different
ages.

     In the  development of MOBILE4.1,  EPA started  out  with the
by model  year version  of  MOBILE4,  since the  ability to see the
differences  in the emission factors  for  each model  year  due to
each revision to the code is useful in error checking.  With the
deletion  of  unnecessary  sections of code  (see  section 1.1.19)
and  some  efficiency improvements, EPA  was able  to  maintain the
by model year option  in  the  final MOBILE4.1  code.   This option
is  accessed through the OUTFMT flag  (see  section 2.1.15).  With
the by model  year  output  available  through  release MOBILE4.1, no
development  or   release  of  a  separate  by model  year version of
the program will be reguired.

1.1.15  Revised  Speed  Correction Factors

     Speed  correction  factors are used  by the model to correct
exhaust emissions  for average speeds other  than  that of the FTP
(19.6  mph).   These  correction factors  have  been  significantly
revised   in  MOBILE4.1.    The  revisions  made   are  based  on
additional  testing  performed  since  MOBILE4,   including testing
over  cycles  with  average  speeds  higher  than  50  mph,  and  a
reanalysis of all  available speed data.

     The   revised   speed  correction  factors  are   different  in
several  ways.   In MOBILE4,  there were  two  speed  regimes for
which  different correction  factor models were  used,  low  speed
(less  than  19.6  mph,  to  a minimum  of  2.5  mph)  and high  speed
(over  19.6  mph,  to a  maximum  of  55 mph).   MOBILE4.1 uses  three
speed  correction  models:   low  speeds  (2.5-19.6  mph),  moderate
speeds  (19.6-48  mph)  and  high speeds  (48-65 mph),  an  approach
that   showed  improved  agreement  between modeled  and  measured
emissions  at  the speeds for which test data are available.
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                              1-21


     This approach addresses one  area  of concern with respect to
the MOBILE4 speed corrections.  At  high speeds  (greater  than 48
mph),  MOBILE4 extrapolated the  correction factors developed from
test data at speeds from 19.6 to 48 mph, to a  maximum  of  55 mph.
Since emissions  were  lower  at higher speeds within  the  range of
the data, this extrapolation  led  to a continued  decrease  in the
emission  factors as  speeds  went from  48 to  55 mph.  With new
test data available from testing  over cycles with average speeds
as  high  as 62  mph,  EPA  was able  to  quantify  the  increase in
emissions  that  occurs as  vehicles  travel  at  higher  speeds.
Thus,  the limits on  the average speed for which  MOBILE4.1 can
estimate  emission  factors  have been  increased,   from  2.5-55 mph
to 2.5-65 mph.

     Speed correction factors  have been  developed for different
model  year groups,   technologies,  and  emission  levels  (i.e.,
normal  emitters  versus  high emitters).   These  corrections are
weighted  together  by  the  fractions appropriate for  each model
years'  vehicles  and  each calendar  years' fleet to  derive the
speed  corrections   applied  to  the  basic  emission  rates.   The
factors  are  also pollutant-specific.   The pattern  of emissions
as  a  function of vehicle  speed  is similar  for  all pollutants,
technologies,   and  model  year groups:   Emissions are greatest at
the  minimum  speed  of  2.5  mph,  decline  relatively  rapidly as
speeds  increase  from  2.5  to 19.6  mph,  decline more  slowly as
speeds  increase  from  19.6  to  48 mph,  and then  increase  with
increasing speed to the maximum speed of 65 mph.

1.1.16  Revisions to Volatility Impact on Exhaust Emissions

     Two  relatively  minor  revisions  have  been  made  to  the
algorithms by which  the impact  of  gasoline volatility  (RVP) on
exhaust  emissions  is  estimated.  First,  the  minimum temperature
at  which  RVP  is  assumed to have  an impact on exhaust emissions
(higher  emissions  at  higher RVP) has been raised slightly,  from
40°F  (4°C) to 45°F  (8°C).   This  change was made on the basis of
analyses  showing that no  consistent trends could be discerned in
exhaust   levels  as   a  function  of   fuel volatility  in   data
collected at  42-43°F  (6°C).   Data at 50° and 55°F (10° and  13°C)
do   show   relatively   small,    but   generally   directionally
consistent,   RVP effects  on   exhaust.    The   increase   in  the
lower-bound temperature  from 40° to  45°F means  that,  since the
volatility  corrections   at  temperatures  between   the   lower
temperature   limit  and  75°F   (24°C)   are based  on  a  linear
interpolation  from  1.0  (no  impact)   at  the  lower  bound,  the
volatility corrections at  temperatures  under  75°F  are  slightly
less than were estimated by MOBILE4.

     At   the  other   temperature  extreme,  the  change  is   more
subtle.   In  MOBILE4,  no  additional  exhaust  reductions   were
modeled   for  reducing  RVP  below  the  test   standard level of


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                              1-22


9.0 psi, unless the temperature was greater than  95°F  (35°C),  in
which  case further  RVP  reductions  (to  a minimum  of  7.0  psi)
provided   additional   reductions   in  exhaust  emissions.    The
underlying   logic,    that  at   very  high   temperatures   even
certification  fuel  (at 9.0 psi  RVP) would  generate  more  vapor
than   is   generated   during   certification  to  the  evaporative
emission standards, and hence that RVPs  below 9.0  psi partially
compensate  for  this  effect,  was  valid.   However,   the  95°F
"cut-off"  in  MOBILE4  resulted in  a  step-function change  in the
emission factors under  certain of  conditions (i.e., 94°F vs 95°F
at RVP < 9.0).

     In  MOBILE4.1,  the  minimum  RVP  below  which  no  further
reduction  can be expected in exhaust  emissions  remains  9.0 psi
at  75°F,  but  as  the  temperature  increases  above  that,  the
minimum  RVP  for which  an   effect  is  modeled  decreases.   The
precise  minimum RVP  associated  with  each  temperature  in  the
75°-95°  range is based on the model year  group-  and technology-
specific  RVP/temperature  correction  factor  equation,  and  so
cannot  be  stated  simply.    However,  the  absolute minimum  RVP
beyond  which  no  further decrease  in  exhaust  emissions  will
result  remains  at  7.0 psi regardless of how high the temperature
rises.   This  smooths  the   step-change   at   95°F,   and   more
accurately  reflects  the  data and  its  analysis  as  expressed by
the RVP/temperature correction factor model.

     As  was true in MOBILE4,  there is no  effect  modeled for RVP
being  less than the  certification level  of  9.0  psi  when the
temperature is less than  75°F (24°C).   Some  test  data indicate
that  possibility that, at temperatures  in the range  of 50-55°F
(10-13°C), the  use  of fuel with  RVP < 9.0 psi  not  only does not
result  in  emission  benefits,  but may actually result  in emission
increases.  The data available  at this  time  are inadequate for
modeling this  possible effect,   but modelers  are  cautioned to
carefully  consider   the   plausibility   of  the  combination  of
temperature and fuel  RVP  that is modeled, and to be aware of the
chance  that  MOBILE4.1  may  underestimate emission  factors  for
conditions combining  low  temperatures  (less  than about 55°F) and
low volatilities (less than 9.0 psi RVP).

     Finally,   an  additional  explanatory  note  concerning  RVP
limits  in  MOBILE4.1  and  their discussion in  this  document.   As
was  true in  MOBILE4,  there  are  actually  two  sets  of  limits on
RVP,  those applicable to  the user input  values  ("period 1" and
"period  2"  in  MOBILE4.1,  formerly  "base"  and  "in-use"),  and
those  applicable to  the  RVP  actually  used to calculate emission
factor   effects (e.g.,   on   exhaust   emissions  or  on  running
losses).   The global limits,  which are  used  to test whether the
user-supplied values  are  valid,  are 7.0 to  15.2  psi  RVP.  These
values  represent the  volatility  of fuel at the pump  — as it is
dispensed  to  the vehicle.


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                              1-23


     Local limits, which are  used to define the range  for  which
emission  factor  effects  are modeled,  refer  to  "weathered"  or
"in-tank" volatility.  As  was explained  in the User's  Guide  to
MOBILE4,[2]  the model accounts  for the fact that fuels "weather"
(experience a decrease in  volatility)  as  they are  driven around
in the  fuel  tank of  a  vehicle.   The  extent  of weathering  is a
function of both  initial RVP  (more volatile fuels  weather  more)
and temperature (weathering is greater at  higher temperatures).

     The  explanation  of the  preceding two paragraphs  does  not
change anything that  was  true of  MOBILE4,  but  is  included here
to ensure that the  difference between the RVP specified as input
(dispensed fuel)  and  the RVP used to calculate emission factor
effects (weathered,  in-tank fuel) is clearly stated.

1.1.17  New Registration Distributions

     EPA  has  updated the registration  distributions  for  all
vehicle  types.   These  distributions  describe  the  fraction  of
vehicles  of  a specific type  (e.g.,  LDGVs)  that are  of each age
from one  to  25-and-older.   MOBILE4  used  "smoothed"  registration
distribution  curves,   based  on  analyses  of  the  actual  fleet
registration   distribution  data   for   recent   years.    These
distributions represented  the best  average distribution for all
calendar  years  modeled,  although  not  necessarily  the  best
possible fit for any specific year.

     In  MOBILE4.1,  with the  focus  on  accurate  characterization
of  calendar  year  1990  emissions,  these distributions  are  not
smoothed;  they  reflect  the  estimated  nationwide  registration
distributions for 1990.

1.1.18  Variable Vehicle Counts

     Vehicle  counts  represent  the  total  number  of  registered
vehicles  for  each of  the  eight vehicle types.   These counts have
been  revised  and  updated in  MOBILE4.1.   The  vehicle  counts
contained  in MOBILE4.1  were  developed  using the MOBILE4  Fuel
Consumption   Model.    That   model   uses   historical   vehicle
registrations  and  sales   and  scrappage  rate  data  to  estimate
vehicle   counts   as   part   of  modeling  highway   vehicle  fuel
consumption.   The  model  uses  data from  a number  of  sources,
including  analyses  and  publications  by  the  Federal  Highway
Administration  (Department  of   Transportation),  the  Oak  Ridge
National  Laboratory  (Department  of   Energy),  the   Bureau  of
Economic  Analysis  (Department  of  Commerce),  the  Motor Vehicle
Manufacturers Association,  and R. L. Polk and Co.

     The  vehicle  counts   in  MOBILE4.1,  in  addition  to  being
revised  to  reflect  the  current  (1990  base  year)  fleet,  also
                                                          07/91

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                              1-24


change  over   time  to  reflect   projected  changes   in   total
registrations.   Additional  information on the  development  of
vehicle  counts  by  calendar  year  in  included   in  the  Fuel
Consumption Model documentation.[7]

1.1.19  Updated Dieselization Rates for LDVs and LDTs

     The series  of mobile  source  emission  factor models has used
dieselization  rates  to indicate  the  fraction  of  vehicles  of  a
given  type  that  are gasoline-fueled  and  the  fraction  that are
diesels.  This approach is used only for light-duty vehicles and
light-duty trucks,  since no data  are  available to indicate that
a  car  or  light  truck  is  used   any  differently  whether   it  is
gasoline-fueled  or  diesel-powered.   The  fleet characterization
data (e.g., annual mileage  accumulation  rates,  average trips per
day  and miles per  day by  vehicle  age)  are  applicable  to the
entire  LDV  or LDT fleet,  as are  the  registration distributions
by  age.   Dieselization   rates   are   used  to  distinguish  the
registration distributions of gas vs.  diesel LDVs  or  LDTs  on the
basis  of  the  fraction  of  vehicle sales of each  type that were
diesel  in each model year.   This  is not done  for  heavy-duty gas
and  diesel  vehicles,  since  the  usage  patterns,  registrations,
mileage  accumulation  rates,  and other   fleet  characterization
data  are  clearly different for the two  types  of vehicle and the
data  necessary to characterize  these  differences  are routinely
collected and  available from a number of sources.

     The  dieselization  rates  are  a   series  of  fractions,  each
associated  with  an  individual model  year,  that  describe what
fraction  of  all  LDVs  or  LDTs   are  diesels.   For  example,  in
MOBILE4,  the   1985  model year diesel  fractions  were  0.009 for
LDVs  (0.9% of MY  1985 LDV sales  were  diesels),   and the LDT
diesel  fraction  was  0.011  (1.1%  of  MY   1985  LDT   sales  were
diesels).  In each new release of the model, these fractions are
updated  on  the basis  of  actual   sales  to  the most  recent  model
year  for  which data  are  available,  and projections  are made of
the diesel fractions for all later model years.

     After reaching  peaks  of about six percent of  LDV sales in
the  1981  model year  and about nine percent  of LDT sales  in the
1982  model  year,  sales of  diesel LDVs   and  LDTs  have  dropped
precipitously.   The latest  data  available for  use in MOBILE4.1
show that the sales  of diesel LDVs in  1988 and later model  years
have  been less  than  0.005 of one percent, and the diesel  share
of LDT  sales  has  fallen to  about  two-tenths of one percent.  The
dieselization rates in  MOBILE4.1 have  been revised to reflect
this  information.

     The problem of  forecasting  future diesel sales  fractions is
illustrated  by  the  rapid  rise and fall  of diesel  sales  in the
late   1970s   and   early  1980s.    In  MOBILE4,   EPA   projected   a


                                                          07/91

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                              1-25


resurgence of  diesel car  and light  truck  sales would  occur  by
the mid 1990s;  a  scenario that  few find plausible  today.   This
problem is handled in two ways  in MOBILE4.1.   First,  much more
modest  future  diesel  sales  fractions  for  model  years  1991
through 2020  are  included  in MOBILE4.1,  based on  manufacturer
projections of  the  future  market.   While  not  foolproof,  these
projections  are  the consensus  of   a  number  of  diesel  engine
manufacturers,  and  are  at least  as  likely  to  be  borne  out  as
were  earlier  projections.   In these projections,   diesel  sales
increase slowly in  the  1990s and the first  15  years of the next
century, reaching  0.3 percent  for  LDVs and 2.15 percent for LDTs
by  model  year  2015.   The model  year  2015  sales  fractions  are
held constant for model years 2016-2020.

     Second,   MOBILE4.1  includes  provisions  for the modeler  to
supply diesel sales fractions as input.   This feature allows the
modeler to account for diesel  sales  fractions  over the past 25
years,  if  they differ  significantly  from  the  national levels,
thus  enhancing  the  accuracy  of  the  base  year   1990  emission
factors and inventories.  This  feature also  allows  actual sales
fractions  for  the  next  few model years to be included  in the
modeling as  the data become available.  Additional information
on  user  input  of  diesel sales fractions  is  in section  2.2.15 of
this document.

     Time did  not permit EPA  to provide the model user  with  a
feature that  would allow the recombining of  gas and diesel cars
and  light  trucks.   Generally,  users  will   have  available  VMT
estimates  for  LDVs  (cars)  and LDTs  (light  trucks)  that  do not
distinguish between VMT accumulated by  gas or diesel vehicles of
each  type.   The scrupulous  inventory developer  will use the VMT
mix  provided  in  the MOBILE4.1  output to  combine  the gas  and
diesel  LDV  (LOT)  emission  factors  for  a  given  calendar  year
before  multiplying   the  combined  all-LDV   (all-LDT)   emission
factor  by the  overall  VMT  for  that  vehicle  type.   Users  who
supply diesel  sales  fractions  as MOBILE4.1  input  in calculating
base  year   1990   emission  factors   should  document   how  the
inventory estimates  were  developed for LDVs  and LDTs,  noting in
particular how the  emission  factors  for  gas  and  diesel  LDVs
(LDTs) were used to derive inventories  for all LDVs  (LDTs).

1.1.20  I/M Benefits for Decentralized  Programs

      In  MOBILE4,  the  benefits  (emission  reductions) attributed
to  I/M  programs were  in  part a function of the type of program
being  modeled:   centralized,  decentralized  computerized,  and
decentralized manual.   The centralized program was  considered to
get  the  maximum  benefit from  a  program  with  the   specified
parameters; decentralized computerized programs were allowed the
same  benefit,  while   decentralized   manual  programs   had  the
benefits  reduced by  50 percent  (relative   to  the  maximum level
achieved by centralized programs).

                                                          07/91

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                              1-24


1.1.19  Updated Dieselization Rates for LDVs and LDTs

     The series of mobile source emission factor  models  has used
dieselization  rates  to  indicate  the  fraction  of vehicles  of  a
given type  that  are  gasoline-fueled  and the  fraction  that  are
diesels.  This approach  is  used only for light-duty vehicles and
light-duty trucks, since  no data  are available to  indicate that
a  car  or  light  truck  is  used  any  differently whether  it  is
gasoline-fueled  or  diesel-powered.   The fleet  characterization
data  (e.g., annual mileage  accumulation rates,  average trips per
day  and miles per  day  by  vehicle  age)  are  applicable to  the
entire  LDV  or LDT fleet,  as are  the  registration distributions
by  age.   Dieselization  rates  are   used   to   distinguish  the
registration distributions  of  gas  vs.  diesel LDVs or LDTs on the
basis of  the fraction of vehicle sales of  each type that were
diesel  in  each model year.   This  is not done  for heavy-duty gas
and  diesel  vehicles,  since the  usage patterns,  registrations,
mileage  accumulation  rates,  and  other  fleet  characterization
data  are clearly different  for the two types of  vehicle and the
data  necessary to  characterize these  differences  are routinely
collected and available from a number of sources.

      The  dieselization rates  are a  series  of  fractions,  each
associated  with  an   individual  model  year,  that  describe what
fraction  of  all LDVs  or  LDTs are  diesels.    For  example,  in
MOBILE4,  the  1985  model  year diesel  fractions were 0.009 for
LDVs  (0.9%  of  MY  1985   LDV  sales were  diesels),  and   the LDT
diesel  fraction  was  0.011  (1.1% of  MY  1985  LDT  sales were
diesels).   In each new release  of  the  model,  these fractions are
updated on the  basis of actual  sales to  the  most  recent model
year  for which data  are  available,  and projections are made of
the diesel  fractions  for  all later model years.

      After  reaching  peaks  of  about  six percent.of  LDV  sales in
the  1981 model year  and  about  nine  percent  of LDT  sales in the
1982  model  year,  sales  of  diesel  LDVs  and  LDTs  have dropped
precipitously.   The  latest  data  available  for use  in MOBILE4.1
show  that  the sales  of diesel  LDVs in  1988 and  later model years
have  been  less than 0.005  of  one  percent,  and  the  diesel  share
of  LDT  sales  has fallen  to  about  two-tenths of one percent.  The
dieselization  rates  in  MOBILE4.1 have  been revised  to reflect
this  information.

      The problem of  forecasting future diesel sales fractions is
illustrated by the  rapid rise and fall of  diesel sales  in the
late  1970s   and early   1980s.    In   MOBILE4,  EPA  projected   a
resurgence  of diesel  car and light truck  sales would  occur by
the   mid  1990s;  a   scenario that  few,  if  any,  find  plausible
today.   This  problem  is  handled  in two  ways  in  MOBILE4.1.
First,  much more modest  future diesel sales fractions  for model
                                                          07/91

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                              1-25


years  1991  through  2020  are  included  in  MOBILE4.1,  based  on
manufacturer  projections  of  the   future  market.    While  not
foolproof, these  projections  are the  consensus of  a number  of
diesel  engine  manufacturers,  and are at  least as likely  to  be
borne  out as were  earlier projections.   In these  projections,
diesel  sales increase  slowly  in  the 1990s and the first 15 years
of  the next century,  reaching  0.3 percent  for  LDVs  and  2.15
percent for LDTs  by model year 2015.  The model year 2015 sales
fractions are held constant for model years 2016-2020.

     Second, MOBILE4.1 includes  provisions  for the  modeler  to
supply  diesel sales  fractions  as input.   This feature allows the
modeler to account  for diesel sales  fractions  over  the  past  25
years,  if they differ significantly  from the national  levels,
thus  enhancing  the  accuracy  of  the base  year  1990  emission
factors and  inventories.   This  feature  also allows  actual sales
fractions for  the next  few  model  years to be included  in  the
modeling  as  the  data become available.   Additional  information
on  user input of  diesel sales fractions is  in  section  2.2.15  of
this document.

     Time did  not permit  EPA to provide  the  model  user  with a
feature that would  allow the  recombining of gas and  diesel cars
and light  trucks.    Generally,   users  will  have  available  VMT
estimates for  LDVs  (cars) and  LDTs (light  trucks)  that  do  not
distinguish between VMT accumulated by gas or diesel vehicles of
each type.  The scrupulous inventory developer will  use  the VMT
mix provided in  the  MOBILE4.1   output  to  combine  the  gas  and
diesel  LDV  (LDT)  emission  factors  for a  given  calendar  year
before  multiplying   the   combined   all-LDV  (all-LDT)   emission
factor  by the  overall VMT  for   that  vehicle  type.   Users  who
supply  diesel  sales fractions as MOBILE4.1  input  in calculating
base   year   1990  emission  factors  should  document   how  the
inventory estimates  were  developed  for  LDVs and  LDTs,  noting in
particular  how the  emission  factors for  gas  and  diesel  LDVs
(LDTs)  were used to derive inventories for all LDVs (LDTs).

1.1.20  I/M Benefits for Decentralized Programs

     In MOBILE4,  the  benefits   (emission  reductions) attributed
to  I/M programs were in part a  function of the type of program
being   modeled:   centralized,  decentralized  computerized,  and
decentralized manual.   The centralized program was considered to
get the  maximum  benefit from  a  program with  the  specified
parameters; decentralized  computerized programs were allowed the
same   benefit,  while  decentralized  manual  programs  had  the
benefits  reduced  by  50  percent   (relative  to  the  maximum level
achieved  by centralized programs).
                                                          07/91

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                              1-26


     This has  been revised  in MOBILE4.1, in  that  decentralized
computerized  programs  are   now  also  subject  to  the  loss  of
50 percent of  the benefits  from the  tailpipe  inspection portion
of the program, as was done  for decentralized  manual  programs in
MOBILE4.  Modelers  who believe that  higher efficiencies  can be
demonstrated  for  a   specific decentralized   computerized  I/M
program  are  encouraged to contact EPA to discuss the issue; see
sections 2.2.5 and 2A.1.12-14 for  additional information.

1.1.21  Miscellaneous Revisions

     Finally,  a  number of smaller  revisions and corrections to
the  code were made  for MOBILE4.1.   Sections  of code  that were
blocked  from execution in release MOBILE4, but  which  had been
used  for EPA's in-house modeling  at  different times,  have been
deleted  to  provide additional capacity  for new  features   (i.e.,
25-model-year  arrays)  while  maintaining  portability  to personal
computers.   Efficiency improvements  (having  no  impact  on the
estimated emission factors)  were  implemented in some sections of
the code.

     As  noted  in  section  1.1, many  of  the  requirements  for the
future   contained  in  the  CAAA  have not   been  implemented in
MOBILE4.1  (the LDT Tier  I  CO emission  standards  and  the  cold-
temperature  CO standards  for LDVs and LDTs  are exceptions) .  For
this  reason,  EPA has  added  a new warning  message  that will be
generated  whenever  the  calendar  year  of  evaluation  is   after
1993.    This  message  simply  notes  that,   since   all  of  the
requirements  contained in the CAAA have  not yet  been coded  into
the model, emission factor projections for  years  beyond 1993 may
not  be  reliable.  This  does  not  mean  that the model  cannot be
used  to  estimate  emission   factors  for  later  years,  but  is
intended to  serve as  a  reminder  to  the  user that not all  CAAA
requirements  are  modeled and  that HC  and   NOx  emission factors
for  later model years must be  viewed with caution.
                                                          07/91

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                              1-27
1.2  LIST OF ABBREVIATIONS USED IN THIS DOCUMENT

     There are a  large  number  of  abbreviations and acronyms used
throughout  this   document.   While  efforts  have  been  made  to
define all  abbreviations  and acronyms  the  first time  that they
appear,  readers  may find  the  following  alphabetized  reference
list   useful.    Further   information   on  those   abbreviations
representing MOBILE4.1  control flags  and  other variable  names
appears in the sections listed at  the end of those definitions.

A/C or AC     Air conditioning, air conditioner
ALHFLG        Control flag  for application of  optional additional
              corrections  to  light-duty  gasoline-fueled  vehicle
              emission factors (section 2.1.10)
alt           Altitude
amb           Ambient
AMBT          Variable name  for user-specified ambient temperature
              (section 2.3.4)
ANSI          American National Standards Institute
AP            Airport
ASCII         American Standard Code for Information Interchange
ASTM          American Society for Testing and Materials
ATP           Anti-tampering program
ATPFLG        Control flag for determination  of  whether effects of
              an ATP on emission  factors  is to be modeled  (section
              2.1.11)

BER           Basic emission rate
bpi           Bytes per inch

CAAA          Clean Air Act Amendments of 1990
CO            Carbon monoxide
CPU           Central processing unit
CVS           Constant volume sampler (sampling)
CY            Calendar year; also,  variable name for calendar year
              of evaluation  (section 2.3.2)

DB            Dry bulb temperature
deg           Degree(s)
DR            Deterioration  rate
DR1           Deterioration  rate   applicable  up to  50,000  miles
              accumulated mileage
DR2           Deterioration  rate  applicable  after  50,000  miles
              accumulated mileage
DSFLAG        Control  flag  indicating  whether  alternate  diesel
              sales  fractions  by  model  year for LDVs  and  LDTs are
              being  supplied as input (see section 2.2.15)

e.f.,  EF      Emission factor(s)
EGR           Exhaust gas recirculation
EKMA          Empirical Kinetic Modeling Approach
EPA           Environmental  Protection Agency

                                                          07/91

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                              1-28
FID
ft
FTP
FTS
°F

g/BHP-hr
g/hr
g/mi
g/min
GVW

HC
HCFLAG

HOD, HDDV
HDG, HDGV

HDV

IDLFLG

I/M
IMFLAG
 Int' I
 I/O
 IOUNEW
JCL

K
     Ibs
LAP
Ib,
LDO
LOOT
LDDV
LOG
LDGT
LDGT1
LDGT2
LDGV
LOT
LDV
LOCFLG
              Flame  ionization  detector
              Feet
              Federal Test  Procedure
              Federal telephone system
              Degrees Fahrenheit

              Grams  per  brake horsepower-hour
              Grams  per  hour
              Grams  per  mile
              Grams  per  minute
              Gross  vehicle weight

              Hydrocarbon(s)
              Control   flag  determining  format  of  HC   emission
              factors  in output (section 2.1.19)
              Heavy-duty diesel vehicle(s)  (over  8500  Ib GVW)
              Heavy-duty  gasoline-fueled  vehicle(s)    (over   8500
              Ib GVW)
              Heavy-duty vehicle(s)

              Control  flag for  output   of  idle  emission  factors
              (section  2.1.17)
              Inspection and maintenance
              Control  flag for  determination of  whether effects of
              an I/M program on emission factors is to be  modeled
              (section  2.1.9)
              International
              Input/Output
              Input   record    for   reassignment   of   I/O   units
              (section  2.1.2)

              Job control language
              Thousand(s)
              Kilogram(s)
            (e.g.,  50K = 50,000)
Local area
Pound(s)
Light-duty
Light-duty
                         parameter  (record)  (section 2.2.8)
                         diesel(s)
                         diesel truck(s)  (0-8500  Ibs GVW)
              Light-duty diesel vehicle(s)
              Light-duty gas
              Light-duty gasoline-fueled  truck(s)
                         to 6,000  Ibs GVW
                                    (0-8500 Ibs GVW)
LDGT(s)
LDGT(s) 6,001-8,500 Ibs GVW
Light-duty gasoline-fueled vehicle(s)
Light-duty truck(s)
Light-duty vehicle(s)
Control  flag  for  location of  local area  parameter
record in input stream (section 2.1.13)
                                                           07/91

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                              1-29
max
MC
min
MPD
mph
MSL
MVMA
myg
MY, MYR
MYMRFG
NAAQS
NEWFLG

NIPER
NMHC
NMHFLG
NMOG
NOx
NT IS

OAQPS
OAR
OEM
QMS
OUTFMT

OXYFLG
PC
PCCC
PCCN

PCHC
PCV
PROJID
PROMPT
Maximum
Motorcycle(s)
Minimum
Miles per day
Miles per hour
Mean sea level
Motor Vehicle Manufacturer's Association
Model year group
Model year(s)
Control   flag    for    input    of   annual   mileage
accumulation  rate data or  registration distribution
data (section 2.1.7)

National Ambient Air Quality Standard
Control  flag  indicating  whether  user  is  entering
modifications to BERs (section 2.1.8)
National Institute for Petroleum  and Energy Research
Non-methane hydrocarbons
Control  flag determining  whether  total  HC  or NMHC
emission   factors  will   be   provided   in    output
(section 2.1.18)
Non-methane organic gasses
Oxides of nitrogen
National Technical Information Service

Office of Air Quality Planning and  Standards
Office of Air and Radiation
Original equipment manufacture(r)
Office of Mobile Sources
Control  flag  indicating  type  of   formatted   output
report to be  produced (section 2.1.15)
Control   flag  indicating  whether   information  on
oxygenated   fuels   (gasoline/alcohol  and  gasoline/
ether  blends)   is  being   supplied  as  input  (see
section 2.2.14)

Personal computer(s)
Variable  name  for percent  of   VMT accumulated  by
catalyst-equipped   vehicles   in   cold-start   mode
(section 2.3.5)
Variable name for percent of VMT  accumulated by non-
catalyst vehicles in cold-start mode (section 2.3.5)
Variable  name  for  percent  of   VMT accumulated  by
catalyst-equipped   vehicles    in   hot-start   mode
(section 2.3.5)
Positive crankcase ventilation
Variable name for MOBILE4 run title (section 2.1.3)
Control  flag determining  if  user  will be  prompted
for  remaining MOBILE4 input (section 2.1.1)
                                                          07/91

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                              1-30
PRTFLG

psi

R

Reg
RLFLAG
rpm
RVP
SIP
SPDFLG
T

TAMFLG

TCP
Tech l-ll,
 Tech IV+
TEMFLG
temp
THC
TOG
TPD

UAM
ub
UDI
veh
VOC
VMFLAG

VMT
VRS

WB

X


ZML
Control  flag determining  which  pollutants
included in output (section 2.1.16)
Pounds per square inch
will  be
Refueling  HC   emission  factor  label   in  numeric
formatted output reports (sections 3.3.1, 3.3.2)
Region
Control  flag  determining  how  refueling  emission
factors will be calculated (section 2.1.12)
Revolutions per minute
Reid vapor pressure

Resting  loss  HC emission  factor  label  in  numeric
formatted output reports (sections 3.3.1, 3.3.2)
State Implementation Plan
Control flag indicating how average  vehicle speed is
to be specified (section 2.1.5)

Running  loss  HC emission  factor  label  in  numeric
formatted output reports (sections 3.3.1, 3.3.2)
Control  flag indicating whether  alternate tampering
rates are to be input (section 2.1.4)
Temperature correction factor
Vehicle technology groups for which different I/M
 emission credits have been developed (sect 2A.1.15)
Control flag indicating how temperatures  for  use in
correcting  emission  factors   are to  be  determined
(section 2.1.14)
Temperature(s)
Total hydrocarbons
Total organic gasses
Trips per day

Urban Airshed Model
Upper bound
Uncontrolled diurnal index

Evaporative  HC  emission  factor  label   in  numeric
formatted output reports (sections 3.3.1,  3.3.2)
Vehicle(s)
Volatile organic compounds
Control  flag  determining  if  alternate  VMT  mix(es)
must be supplied as input (section 2.1.6)
Vehicle miles travelled
Vapor recovery system

Wet bulb temperature

Exhaust   HC   emission   factor   label   in  numeric
formatted output reports (sections 3.3.1,  3.3.2)

Zero-mile level
                                                          07/91

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                         1-31
               References for Chapter 1
"Guidance  on  Estimating Motor  Vehicle Emission  Reductions
from  the  Use  of  Alternative Fuels  and Fuel  Blends,"  U.S.
EPA, Office of Air and Radiation, Office  of  Mobile Sources,
January 1988,  EPA-AA-TSS-PA-87-4.

"Procedures for Emission Inventory Preparation,  Volume IV:
Mobile  Sources,"  U.S.  EPA,  Office  of Air  and  Radiation,
Office  of  Air Quality Planning and Standards  and Office of
Mobile Sources, May 1991, EPA-450/4-81-026d (revised).

"User's  Guide to  MOBILE4,"  U.S.  EPA,  Office  of Air  and
Radiation,    Office    of   Mobile   Sources,    May   1989,
EPA-AA-TEB-89-01 .

"Refueling Emissions  from Uncontrolled Vehicles," U.S.  EPA,
Office  of  Air and   Radiation,  Office of Mobile Sources,
1985, EPA-AA-SDSB-85-6.

Letter  from  Philip S. Bush,  Amoco  Oil Co.,  to  Charles L.
Gray, Jr.,  Director,  Emission Control  Technology Division,
January 7, 1987.

"Adjustment  of MOBILE4  Idle CO  Emission  Factors to  Non-
Standard Operating Conditions," U.S.  EPA,  Office  of Air and
Radiation, Office of Mobile Sources, November 1989.

"The  MOBILE4  Fuel Consumption Model,"  U.S.  EPA,  Office of
Air and Radiation, Office of Mobile Sources, 1991  [DRAFT].
                                                     07/91

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                            Chapter 2

                         MOBILE4.1  INPUTS
2.0  INTRODUCTION
     The  reader  is  encouraged  to  refer  to  the   examples  in
Chapter 5  when  reading  this  chapter.    These  examples  provide
illustrations  of  the  use  of  MOBILE4.1  options  and  data  input
requirements.

     MOBILE4.1  utilizes  one  input  data  set that provides  program
control  information and  the  data  describing  the  scenarios  for
which  emission factors are  to be  estimated.   The input data set
consists  of  three  distinct   sections:   the Control  section,  the
One-time data section,  and the Scenario section.

     The  Control  section  is  the portion  of the  input  data  that
controls  the input, output,  and execution of  the  program.   For
example,  the  Control   section  indicates   whether  MOBILE4.1  will
prompt  the  user   for  input  data,  or  analyze  a  scenario  that
includes  an  inspection   and  maintenance  program,  or  output  the
emission  factors  in a  format  suitable for visual inspection  or  in
a format suitable as input for another program.

     Some   of  the  parameters  used   in   the  emission   factor
calculations   have   internal,  or  default,   values    built   into
MOBILE4.1.   The One-time  data section is the portion  of  the input
data  that allows  the  user to define parameter values  different
from  those  internal  to   MOBILE4.1,  which  will  be   used  in  the
calculations  for  all  of  the  scenarios  within  a  given  run.   For
example,  in  the One-time data  section the  user can  specify annual
mileage  accumulation rates or registration distributions  by  age
for each vehicle type.

     The  Scenario  section  is the  portion  of   the MOBILE4.1  input
data  that  details  the  individual  scenarios   for  which  emission
factors   are  to  be  calculated.   For  example,  in  the  Scenario
section  the  user  specifies the calendar year  of evaluation,  the
average  speed(s)   to  be  assumed,   and  the  region  (low- or  high-
altitude) .

     In  a few cases,  the  placement of data  in  either  the One-time
data  section or  the Scenario  data section is determined by the
setting  assigned  to a  flag   in  the Control section  of  the  input
stream.   In such  cases,  discussion of the  variable(s)  involved is
provided  once  (usually in  the One-time section),  and  is referenced
in the other  (usually the Scenario) section.
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                               2-2

     The  Control  section  consists primarily  of specified  values
for variables  termed  flags.   In  section  2.1 each  flag is  named,
and the range  of possible  settings for that flag and the resulting
action  is noted.   In  the One-time   and  Scenario  data  sections
(sections 2.2  and  2.3 respectively),  the  following  general  format
is used.   (Depending  on the  variable being  discussed, not  every
item noted below is included for every variable.)

     DescriptIon:    A  brief  description   of   what   the  variable
means, and how it is used by MOBILE4.1.

     Options:  A  summary  of  choices  available  to  the  MOBILE4.1
user.

     Use  i n  MOB ILE4.1:   A description  of  the  value(s)  used  in
MOBILE4.1 for the variable(s)  if the user  does  not  input locality-
specific  information,  where  applicable,  and discussion of  how the
information is used in the emission factor calculations.

     Required  Information:   A  specific  description  of  exactly
what  information  is  required  of  the  user,   where  applicable,
including format specifications.

     Changes   Since  MOBILE4:   A  statement  summarizing  exactly
what  changes have  been  made in  the  variable  since  MOBILE4.   Not
every variable has been revised.  For  those  that  have  changed,
this  section  highlights  exactly  what is  different  in MOBILE4.1
relative  to  MOBILE4 (options, format  requirements,  or  use  within
the model).

     Guidance:    Where  applicable,   EPA's  recommendations   and
suggestions  with  respect  to  the determination  of  user-supplied
values  for  the  variable(s)   under  discussion.   Many  users  of
MOBILE4.1 will be  involved in the development  of base-year  (1990)
emission  inventories  for  use  in  the  State   Implementation  Plan
(SIP) process.  In  many cases, there  is  no single  correct  answer
or recommendation that will be the best answer for  all areas.   For
those using  MOBILE4.1  to estimate highway mobile source base-year
emission  inventories  in response to the  requirements  of the Clean
Air Act Amendments  of 1990,   it  is important that the appropriate
EPA  Regional  Office  personnel  be  kept  involved  in  decisions
concerning questionable  or  controversial  assumptions  and  steps  in
the modeling.

     There is  also  an appendix to this chapter which discusses the
terminology  used  to   describe  inspection and  maintenance  (I/M)
programs  and  anti-tampering  programs.   Appendices  2B  and  2C  from
the User's  Guide to MOBILE4  have been deleted:   Guidance  on the
determination  of  appropriate  values for temperatures  and  fuel
volatility   (RVP)   appears   in  the   revised   emission  inventory
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                               2-3

guidance   ("Procedures   for   Emission   Inventory   Preparation,
Volume IV:    Mobile    Sources,"   EPA-450/4-81-026d    (revised),
July 1991), and there  is  no longer any need to  determine  the ASTM
volatility class in modeling emission factors (see section 2.2.10).

     Questions   about   the   material   in  this   document,   and
suggestions  as   to how  the  MOBILE4.1  User' s  Guide  may  be  made
clearer and more useful, should be addressed to:

                 Terry P.  Newell (TEB-13)
                 U.S.  EPA Motor Vehicle Emission Laboratory
                 2565 Plymouth Road
                 Ann Arbor, MI   48105

                 (313) 668-4462  or  FTS 374-8462

     The  remainder of  Chapter 2  is  structured  as it was  in the
User's  Guide  to MOBILE4.   For  the most  part,   the  same  section
numbers  correspond to  the same  inputs  and discussions as  in the
previous  User's Guide.   Where  applicable, new subsections  have
been added to clearly indicate changes relative to MOBILE4.
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                               2-4

2.1  CONTROL SECTION

     The first  portion of  the input  stream for  a MOBILE4.1  run
consists primarily  of  a series  of  flag  settings.   These  flags
control  the  format  (and  in  some  cases  the  content)  of  the
remainder  of  the  input  stream,  influence  the  execution of  the
program, and  determine  the content  and  format  of the  program's
output.  Each flag  is named,  defined,  and its  possible  values
listed, along with the effect of each setting.


2.1.1  PROMPT

     2.1.1.1  Description

     This  flag  determines whether  the  user will  be prompted  for
the  remainder of  the  input stream,  and  the  arrangement  of  the
remaining Control data section input.

     2.1.1.2  Values/Actions

     This flag can be set to 1, 2, 3,  or 4:

        Value     Action

          1     No prompting; after PROJID record (section 2.1.3),
                vertical  format  (one value per  line/record)  used
                for remainder of Flags input
          2     MOBILE4 prompts for each input;  vertical format
          3     No  prompting;  after   PROJID   record,   horizontal
                format  (all values  on  one line/record)  used  for
                remainder of Flags input
          4     MOBILE4 prompts for each input;  horizontal format

It  is  suggested  that  the input prompting options (PROMPT = 2 or 4)
be  used only when  the  user is uncertain  as to  the order  of  the
remaining inputs in the Control data section.

     2.1.1.3  Changes Since MOBILE4

     If the value  of  PROMPT is either  2 or 4,  indicating that the
user wishes to  be  prompted for the remaining input  data,  the data
to  be  entered  is  entered on  the  same  line  as  the  prompting
message.   (In MOBILE4, the user was to  enter the  requested data on
the  line following each prompting message.)
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                               2-5

2.1.2  IOUNEW

     2.1.2.1  Description

     The  IOUNEW flag  allows  reassignment  of  output unit  device
numbers.   There  are  three different  types  of program output,  and
the  default  value for  all  three  is unit  6.  This  flag is  only
useful when  the mainframe computer  version of MOBILE4.1  (9-track
magnetic  tape)  is being  operated.   The personal  computer  version
of MOBILE4.1 does not permit the reassignment of I/O devices.

     2.1.2.2  Values/Actions

     The  three  types  of  program  output are:   formatted  reports
(emission factor  results),  diagnostic messages  (error  and warning
messages), and prompting messages (such as  are  issued if  the value
of  the  PROMPT   flag  above  is  2  or  4).    Single integer  values
representing other I/O  device numbers may  be assigned for  any or
all  of these, in the order listed.   If no device reassignments are
desired, these fields may be left blank.

     Values of  1,  2,  3,  6, 7, and 8  are allowed  by  MOBILE4.1 for
assignment of any  of the three possible output units.  Values of 4
and  5  are reserved  as  input device  codes  in MOBILE4.1,   and  thus
may  not  be  assigned  by  the  user  for  any  IOUNEW field.   If an
illegal  or  missing  IOUNEW  value  is  encountered, MOBILE4.1  will
revert to the default value (unit 6).  The user  is cautioned that
IOUNEW values considered valid by MOBILE4.1 may not be appropriate
for  a given computer system.


2.1.3  PROJID

     2.1.3.1  Description

     MOBILE4.1 provides an  80-character  alphanumeric  field for the
user to  input a descriptive title for the MOBILE4.1 run.

     2.1.3.2  Values/Action

     The project  title is an 80-column blank record.  The user may
use  up  to 80 characters for the title.  The character  string does
not  have to  be left-justified.  Whatever  title  is  input  by the
user  is  echoed  as the heading of the  formatted reports  section of
the  program output.    If  no  title is  desired,  a blank record must
be entered here.
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                               2-6

2.1.4  TAMFLG

     2.1.4.1  Description

     This flag  provides the  option of  supplying tampering  rates
that differ  from those included in the MOBILE4.1 code.

     2.1.4.2  Values/Action

     This flag can be set to 1 or 2:

        Value     Action

          1      Use MOBILE4.1 tampering rates
          2      User supplies tampering rates  for  eight categories
                of  tampering,  for each of  the four vehicle  types
                affected by tampering (LDGV, LDGT1, LDGT2, HDGV)

The user-supplied tampering rate data,  required if TAMFLG =  2,  are
placed  in  the  One-time  data  section.   Section  2.2.1  discusses
tampering rates as program input.

     2.1.4.3  Changes Since MOBILE4

     As  discussed  in  section  2.2.1,  tampering  rates  are  now
applicable  to  three model  year  groups of  light-duty  vehicles,
rather than the two model year groups used  in  MOBILE4.   This  means
that if  the  user  sets the value of TAMFLG  = 2,  additional sets of
tampering rate  equations must  be supplied.   See section  2.2.1  for
additional information.


2.1.5  SPDFLG

     2.1.5.1  Description

     MOBILE4.1 requires that vehicle average speed be  specified in
the  program  input,  since exhaust  and running  loss  emissions vary
considerably  with  speed.   This  flag   provides   the  option  of
specifying one  speed  for  all eight vehicle types, or of  specifying
different speeds for each vehicle  type.   In addition,  in MOBILE4.1
there  are two new  values  of SPDFLG that can be  used  to indicate
that the user wishes  to supply  data  on  the distribution of  trips
by  length  (of  time) for  use  in the estimation  of  running loss
emission factors.
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                               2-7

     2.1.5.2  Values/Action

     This  flag  can be  set  to  1,  2,  3,  or  4:

        Value     Action

          1      User supplies one  value  for speed to be applied  to
                all vehicle types
          2      User  supplies  eight  values  for  speed, one  to  be
                applied to each vehicle  type
          3      User supplies one  value  for speed to be applied  to
                all vehicle types,  and a different  set  of  locality-
                specific  VMT  fractions by  trip  length  (for use  in
                running  loss  emission   factor   calculations)   for
                each scenario in the  Scenario data  section
          4      User  supplies one value  for  speed  to be applied  to
                all vehicle  types, and a single  set of values  for
                locality-specific   VMT  fractions  by   trip  length
                (for    use   in   running   loss   emission   factor
                calculations) in the  One-Time data  section

     2.1.5.3   Changes  Since MOBILE4

     If the value  of  SPDFLG  is  1 or 2, there  are no differences
from MOBILE4  in how the speed data are located or  formatted  in  the
input file.  The values  of  3  and 4  are new  options in MOBILE4.1.
If either of these values is selected,   only a  single speed  input
to be  used  for all eight vehicle classes  can be  used (equivalent
to SPDFLG = 1), and the  user must supply  alternate information  on
the  fraction   of VMT   that   is  accumulated  in  trips  of  different
lengths.  The  alternate   locality-specific VMT   fractions by  trip
length may be  placed   in  the One-Time data  section, in which  case
those values will be  used in all  scenarios of the run,   or  in  the
Scenario data  section.  Section 2.3.3 and  2.3.11 discuss  speed and
VMT fractions by trip  length, respectively, as program  input.


2.1.6  VMFLAG

     2.1.6.1  Description

     The  setting of  VMFLAG  determines  the vehicle miles  travelled
(VMT) mix  (fraction of total VMT  accumulated by vehicles of  each
of the  eight types) that  will be used in MOBILE4.1 to  estimate the
composite emission factor for a given scenario.
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                               2-8

     2.1.6.2  Values/Action

     This flag can be set to 1,  2,  or 3:

        Value     Action

          1     Use MOBILE4 VMT mix
          2     User supplies a different VMT mix for each scenario
          3     User supplies a single VMT mix for all scenarios

If VMFLAG =  2,  the VMT mix input data are placed in  the Scenario
data section.   If  VMFLAG  = 3,  the VMT mix input data are placed in
the One-time  data section.  Sections  2.2.2  and 2.3.6  discuss  VMT
mix as  program input.  There have  been no  revisions  to this flag
since MOBILE4.


2.1.7  MYMRFG

     2.1.7.1  Description

     This  flag controls  the  use  of  annual mileage  accumulation
rates  by  age  and   registration  distributions   by  age.    These
parameters  define the  composition  and  travel characteristics  of
the fleet, and so affect the resulting emission factors.

     2.1.7.2  Values/Action

     This flag can be set to 1, 2,  3, or 4:

        Value     Action

          1     Use  MOBILE4.1   (national   average)  annual  mileage
                accumulation rates and registration distributions
          2     User  supplies  annual  mileage  accumulation  rates;
                use MOBILE4.1 registration distributions
          3     User   supplies   registration   distributions;   use
                MOBILE4.1 annual mileage accumulation rates
          4     User  supplies  both  annual  mileage  accumulation
                rates and registration distributions

The  input data required  if MYMRFG  = 2,  3,  or  4  are placed in the
One-time  data section.   Section 2.2.3 discusses the  input  and use
of    annual   mileage   accumulation    rates    and   registration
distributions.  There have been no  revisions  to this  flag since
MOBILE4.
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                               2-9

2.1.8  NEWFLG

     2.1.8.1  Description

     This flag  provides  the option of modifying  the  basic exhaust
emission rates by model year.

     2.1.8.2  Values/Action

     This flag can be set to either 1 or 2:

        Value     Action

          1     Use MOBILE4.1 basic exhaust emission rates
          2     User  supplies  one or  more  modifications to  the
                MOBILE4.1 basic exhaust emission rates

The  user-supplied  modifications  to  the  basic  emission  rates,
required  if  NEWFLG =  2,  are placed  in  the One-time  data section.
Section  2.2.4 discusses  basic exhaust  emission  rates  and  their
modification  by the  user.   There have  been no  revisions  to this
flag since MOBILE4.


2.1.9   IMFLAG

     2.1.9.1  Description

     This  flag  allows the  option of having  MOBILE4.1  include the
emission benefits  of  an  operating inspection and maintenance (I/M)
program on the emission  factors.

     2.1.9.2  Values/Action

     This flag can be  set to  1 or 2:

        Value      Action

          1     No I/M program is assumed  to  be operating
          2     User  specifies an I/M program and MOBILE4.1 models
                its impact  on emissions

The  data specifying  an I/M  program,  required if IMFLAG  = 2, are
placed   in   the   One-time   data   section.   Section   2.2.5  and
Appendix  2A  discuss  the specification  of I/M programs  and their
use  in MOBILE4.1.  There have been no revisions  to this flag since
MOBILE4.
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                               2-10

2.1.10  ALHFLG

     2.1.10.1  Description

     This flag  provides  the ability to have MOBILE4.1  adjust some
exhaust  emission  factors to  account for  certain conditions:  air
conditioning  (A/C)  usage,   extra  loading,  trailer  towing,  and
humidity.   These   additional  corrections   apply  only  to  exhaust
emission  factors  (HC, CO,  and NOx),  and  only  to  the  light-duty
gasoline-fueled vehicle  types  (LDGVs,  LDGTls,  and  LDGT2s),  with
the  exception  that  the  humidity  correction  affects  only  NOx
emission factors and is also applied to motorcycle emissions.

     2.1.10.2  Values/Action

     This flag can be set to 1,  2, or 3:

        Value     Action

          1     Do  not  apply these  additional  correction  factors
                (no additional inputs required)
          2     Six additional input values required
          3     Ten additional input values required

The additional  data required  if ALHFLG = 2 or 3 are placed  in the
Scenario  data   section.    The   specific   inputs   required  when
ALHFLG = 2  or  3 are  discussed  in section  2.3.8.   There have been
no revisions to this flag since MOBILE4.


2.1.11  ATPFLG

     2.1.11.1  Description

     This  flag  allows  for  the   benefits  of  an operating anti-
tampering  program  (ATP)  to  be  included   in  the emission  factor
calculations.

     2.1.11.2  Values/Action

     This flag can  be set to  1 or  2:

           Value     Action

             1      No ATP is  assumed
             2      User  specifies  an  ATP  and  MOBILE4.1   accounts
                    for its  impact  on emissions

The  data specifying the characteristics of the  ATP to be  modeled,
required  when  ATPFLG  =   2,  are placed  in   the  One-time data
section.  Section  2.2.6  and Appendix 2A discuss user specification
of ATPs.  There have been no  revisions  to this flag  since MOBILE4.
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                               2-11

2.1.12  RLFLAG

     2.1.12.1  Description

     This flag controls whether and how  MOBILE4.1  models refueling
emissions (also  referred to as Stage  II  emissions)  from gasoline-
fueled vehicles.

     2.1.12.2  Values/Action

     This flag can be set to 1, 2, 3,  4,  or 5:

           Value     Action

             1     Use  uncontrolled  refueling  emission rates  for
                   all model years
             2     Model  the  impact  of  Stage II  vapor  recovery
                   system (VRS) requirement on refueling emissions
             3     Model  impact  of  onboard  VRS  requirement  on
                   refueling emissions
             4     Model  impact  of both  Stage  II  and  onboard  VRS
                   requirements on refueling emissions
             5     Zero-out    refueling    emissions    completely
                   (effectively the approach  taken in MOBILES);  in
                   this case,  Stage II emissions  must be accounted
                   for  in  the stationary source  portion of  the
                   emission inventory

The  data describing the  characteristics  of  either  or  both  vapor
recovery  systems,  required if RLFLAG  =  2, 3,  or  4,  are placed in
the One-time data  section.   Refueling  emissions and their modeling
in MOBILE4.1  are  discussed  in section 2.2.7.  There  have been no
revisions to this  flag  since MOBILE4.


2.1.13   LOCFLG

     2.1.13.1  Description

     This  flag  controls  the input by the user of  the local area
parameters   (LAP)  record.   This  record  contains  six  to  eight
fields:   scenario  name,  minimum  and maximum  daily temperatures,
base  (or pre-control)  RVP,  in-use  (or   control)  RVP,  in-use  RVP
control  start year,  and  possibly values for OXYFLG  and DSFLAG.
The  ASTM volatility class,  which was a  required  part of  the  LAP
record  for  MOBILE4, is no longer necessary.   However,  the  format
of the remainder of the record is  unchanged,  so that a MOBILE4 LAP
record  that includes ASTM class  will  function as MOBILE4.1  input.
The  two  optional  "flag" values,  OXYFLG  and  DSFLAG,   are  used to
indicate whether the  user is  inputting data on an oxygenated fuels
program  and on  alternate  diesel  sales  fractions by  model  year.
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                               2-12

They follow  the  in-use RVP control start year, and  if  missing are
interpreted  by MOBILE4.1  as indicating  that  neither type  of  data
are  included.  Thus,  a LAP  record from a MOBILE4  input  file  will
work in MOBILE4.1.

     2.1.13.2  Values/Action

     This flag can be set to 1 or 2:

           Value     Action

             1     User  enters  a  distinct  LAP  record  for  each
                   scenario of the MOBILE4.1 run
             2     User  enters  one  LAP  record  to  apply  to  all
                   scenarios of the MOBILE4.1 run

If  LOCFLG =  1,  the  LAP  records  are  placed  in  the Scenario  data
section.  If LOCFLG = 2,  the LAP  record is placed  in  the One-time
data  section.    The   content  of  the  LAP  record  is discussed  in
section 2.2.8, and the individual  variables comprising  the  LAP are
discussed in sections 2.2.9 through  2.2.15.   Table 2.2-5 provides
a  summary  of  and  specifications  for  the  LAP  record  in  the
MOBILE4.1 input stream.

     There  have  been  no  revisions  to LOCFLG  since MOBILE4.   The
revisions  to the  content  of  the  LAP  record  are  discussed  in
sections 2.2.8 through 2.2.15.


2.1.14     TEMFLG

     2.1.14.1  Description

     This  flag controls  the determination of temperatures to  be
used  in the  correction of  the  exhaust emission factors (HC, CO,
and  NOx), the  hot  soak  and diurnal components of  the evaporative
HC  emission  factors,  and  the  running loss  and resting  loss  HC
emission factors.  All of these  are dependent on  temperature.

     2.1.14.2  Values/Action

     This flag can be  set to 1 or  2:

           Value     Action

             1     MOBILE4.1 will  determine  the temperatures to be
                   used   in  correcting  emission factors  on  the
                   basis  of   the   input  values   of  minimum  and
                   maximum  daily temperature.   The  input value of
                   ambient   temperature  will   not  be   used  in
                   calculating     temperature     corrections    to
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                               2-13

           Value     Action

             1     (continued)  emissions if TEMFLG =1;  it will  be
                   overridden   by   specific   values   calculated
                   individually   for   exhaust  HC,   exhaust   CO,
                   exhaust  NOx,  hot   soak   evaporative HC,   and
                   running loss HC.

             2     The input value  of  ambient temperature will  be
                   used in calculating  the temperature corrections
                   to all  exhaust emissions, hot  soak evaporative
                   emissions,   and  running  and   resting   loss
                   emissions.   The  input  values  of  minimum  and
                   maximum daily  temperature  will  still  be  used to
                   calculate diurnal evaporative emissions.

     The   temperatures   used   to   correct   exhaust,   hot   soak
evaporative,  and  running  loss  and resting loss  emissions  are
determined in a way that accounts  for variation  in emission  levels
with daily  variation in temperature if TEMFLG =  1.   The result is
that the  temperature corrections  are weighted  to  reflect  average
emissions  over  a  period  of  time  (i.e.,  one  day)  where  the
temperature range  is  from the  minimum  to  the maximum temperature.
Thus  the use  of  TEMFLG  =  1  is  recommended  for daily  emission
inventory preparation and SIP-related modeling by the States.

     For those areas modeling emission  factors on an  hourly basis,
whether  required for  input  to  other  air  quality models  (such as
Urban Airshed)  or for  some  other purpose,  the  use of  TEMFLG  = 2
will  be more  appropriate.   When  TEMFLG  =  2,  the input value of
ambient temperature  should be  selected  to represent  conditions in
the  short  time period  (one  hour)  being modeled.   This temperature
will  then  be used to correct  exhaust,  hot   soak  evaporative,  and
running loss and resting loss emission factors.

     The  input  of  minimum  and  maximum  daily  temperatures  is
discussed in  section 2.2.11.   The input of  ambient  temperature is
discussed   in   section   2.3.4.    Additional   guidance  on   the
determination of  appropriate values for use  as  temperature  inputs
to  MOBILE4  when the  model is  being used  for SIP-related emission
inventory  development  and  attainment  planning  is  provided  in
"Procedures for  Emission  Inventory Preparation,  Volume IV:   Mobile
Sources," EPA-450/4-81-026d  (revised),  July  1991.

     There have been no revisions to TEMFLG  since MOBILE4.
     Table  2.1-1   summarizes   the  flags  controlling  the  input
requirements and execution of MOBILE4.
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                               2-14

2.1.15  OUTFMT

     2.1.15.1  Description

     This  flag controls  the  format  structure  of  the  formatted
output report.  Different  formats  are appropriate  depending on the
intended use of the MOBILE4.1 output.

     2.1.15.2  Values/Action

     This flag can be set to 1, 2, 3, 4, or 5:

           Value     Action

             1     222-column numerical format
             2     140-column numerical format
             3     112-column descriptive format
             4      80-column descriptive format
             5     By-Model Year output (in addition to standard
                    112-column descriptive format)

The  numerical  formats  are generally  used  when the output  of the
MOBILE4  run  is to be used as  input  for  another  program (e.g., air
quality  simulations).   The descriptive  formats  contain all  of the
same  information,  with  more  complete labels and headings  for ease
of   visual  inspection.    Illustrative  examples  are  shown  in
Chapter  5  (MOBILE4.1 Examples).

     2.1.15.3  Changes Since MOBILE4

     The first four  options  for output format are exactly  as they
were  in  MOBILE4.   The  last  option  (OUTFMT =  5) provides the user
the  ability   to   obtain   additional  output   tables   listing  the
emission factors  for  vehicles  of each model year (vehicles of ages
l,  2,  ...,  25+  in  the  calendar year  of  evaluation).   If  this
option is  selected additional input must be  provided,  in the form
of  one  additional record  in  the  One-Time   data  section.   This
additional record tells  MOBILE4.1 which vehicle types the by-model
year output is desired for, and is described in section 2.2.16.


2.1.16   PRTFLG

     2.1.16.1  Description

     This  flag  determines  which  pollutants will  have  emission
factor calculations  performed, and  thus will  be  included  in the
program  output.   This feature  enables the user to  avoid the time
and  expense  of calculating  all  emission factors when  the results
for  only one of the pollutants are  all  that  is  necessary for some
applications.
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                               2-15

     2.1.16.2  Values/Action

     This flag can be set to 1, 2,  3,  or 4:

           Value     Action

             1     HC (hydrocarbon) emission factors only
             2     CO (carbon monoxide) emission factors only
             3     NOx (oxides of nitrogen)  emission factors only
             4     All three pollutants

     There have been no revisions to this flag since MOBILE4.


2.1.17  IDLFLG

     2.1.17.1  Description

     This  flag  controls   the  calculation  and  output  of  idle
emission factors (emissions at idle in terms  of  mass pollutant per
unit time (g/hr) for each pollutant).

     2.1.17.2  Values/Action

     This flag can be set to 1 or 2:

           Value     Action

             1     No idle emission factors calculated or printed
                     (exhaust emission factors only)
             2     Idle emission factors calculated and printed
                     (in addition to exhaust emission factors)

     There have been no revisions to this flag since MOBILE4.


2.1.18  NMHFLG

     2.1.18.1  Description

     This  flag determines which of five possible  options  for the
hydrocarbon  emissions factors  will be  used in  the calculations:
total    hydrocarbons,    including    methane   (THC);   non-methane
hydrocarbons,  defined   as   THC minus  methane  (NMHC);  volatile
organic  compounds,  defined  as NMHC  minus  ethane  corrected for
aldehydes  (VOC); total organic  gases,  defined as THC corrected for
aldehydes  (TOG);   or non-methane  organic  gases,  defined  as NMHC
corrected    for    non-hydrocarbon   reactive    compounds,     i.e.,
formaldehyde and acetaldehyde  (NMOG).  These are summarized below:
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                               2-16

                      Compounds included  in the  emission factors
          Option      FID HC    Methane      Ethane      Aldehydes

            THC         Yes        Yes          Yes           No
           NMHC         Yes        No          Yes           No
            VOC         Yes        No          No          Yes
            TOG         Yes        Yes          Yes          Yes
           NMOG         Yes        No          Yes          Yes

     2.1.18.2  Values/Action

     This flag can be set to 1, 2, 3,  4,  or 5:

           Value     Action

             1     Total hydrocarbon emission factors (THC)
             2     Non-methane hydrocarbon emission factors (NMHC)
             3     Volatile  organic  compounds (VOC)
             4     Total organic gases (TOG)
             5     Non-methane organic gasses (NMOG)

     2.1.18.3  Changes Since MOBILE4

     The  first  two  options  for NMHFLG  have the   same  meaning and
result  as  in  MOBILE4.   The  last  three  options   are  new  in
MOBILE4.1,  and  provide  the  user the  ability to  estimate highway
motor vehicle HC  emission factors that  include  or exclude various
compounds  depending  on  the  application  intended   for  the results.
See section 1.1.2 for additional discussion  of  these options.   For
guidance  on the  most  appropriate  choice  for  the  preparation  of
base  year  emission  inventories,  see  "Procedures   for  Emission
Inventory     Preparation,     Volume  IV:     Mobile     Sources,"
EPA-450/4-81-026d (revised), July 1991.


2.1.19  HCFLAG

     2.1.19.1  Description

     This   flag  determines   whether   the  HC  emission  factors
displayed  in  the  output  will  include   only  the  sum  of  all
components of HC  emissions  (whichever composition  option for these
emissions  is  selected)  or will also include the various component
emission  factors  (exhaust,   evaporative,  refueling,   running loss,
and total HC emissions).  This flag also  allows the  user to select
an expanded  printout of the various components  of  "evaporative" HC
emissions, as discussed  in section 1.1.3.
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                               2-17

     2.1.19.2  Values/Action

     This flag can be set to 1, 2,  or 3:

           Value     Action

             1     No component  output  (print only  sum  of all  HC
                   components)
             2     Print sum and components  (exhaust,  evaporative,
                   refueling, running loss,  and resting loss HC)
             3     Print sum and components  (exhaust,  evaporative,
                   refueling,  running loss,  and resting  loss  HC),
                   and a detailed evaporative breakdown in grams

     2.1.19.3  Changes Since MOBILE4

     The first two options for this flag have  the  same meaning and
result  as  in MOBILE4.   The last  option provides  the user with a
detailed   breakdown   of   the   various   types  of   "evaporative"
emissions.    The   emission  factors  presented   in   the  expanded
evaporative  emission factor table are  in  grams  per  event  (trip
end)  for hot soak evaporative emissions,  grams per  event (period
of   rising  ambient  temperature   without   trips)    for   diurnal
emissions,   grams  per  gallon  of  fuel  dispensed  for   refueling
emissions,   and  grams per  hour  for  resting  losses.   The  running
loss  emission factors can  only be expressed as grams per mile, and
are shown in the component output produced when HCFLAG =  2 or 3.


Table 2.1-2 summarizes the flags controlling the output of MOBILE4.


2.1.20   Inter-Flag Dependencies

      2.1.20.1  Description

      There are  cases where the value assigned to one flag  in the
Flags section either determines the value that must be assigned to
another  flag, or  precludes the use of one or  more possible values
for   another  flag.   Certain  combinations  of  flag  settings  also
impose  requirements  on other  inputs  in  either  the One-time  or
Scenario data  sections.  While  careful consideration  of the input
file  prepared for  a MOBILE4.1  run makes  such  situations  clear, a
short listing is provided here for the convenience of the user.

      2.1.20.2  List

      2.1.20.2.1  If  TAMFLG  = 2 (user-supplied tampering  rates)  and
                 IMFLAG  =  1 (no I/M program  assumed), supply only
                 one  set  of  alternate tampering  rates  (non-I/M
                 rates).
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                               2-18

     2.1.20.2.2  If TAMFLG = 2  and  IMFLAG =  2  (specify and  model
                 an I/M program), two sets of  alternate tampering
                 rates must be  supplied (non-I/M and I/M rates).

     2.1.20.2.3  If PRTFLG -  2  or  3  (no   HC  emission   factors
                 requested), then the flags  dealing with  details
                 of the HC emission  factor  calculation should  be
                 set  as  follows:   NMHFLG =  1,  HCFLAG -  1,  and
                 RLFLAG =  5.

     2.1.20.2.4  Conversely, if  NMHFLG   >.  2  and/or  HCFLAG  =  2
                 and/or RLFLAG = 1,  2, 3, or  4,  then PRTFLG = 1 or
                 PRTFLG =  4 is  necessary.

     2.1.20.2.5  If the user has elected  to  input  alternate diesel
                 sales fractions by model year for  LDVs and LDTs,
                 then  LOCFLG  =  1   (a separate  LAP  record to  be
                 entered for each scenario)  is mandatory.

The  last  of  these restrictions is new in MOBILE4.1.   See  sections
2.2.8 and 2.3.10 for additional information.
This concludes the Control data section.
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                               2-19

2.2  ONE-TIME DATA SECTION

     As suggested by  its  name,  the One-Time data  section contains
information  which  is  input  only  once  in a given  MOBILE4.1  input
file.  This  input  information  is  used  to  alter  data  internal  to
MOBILE4.1  to  reflect   locality-specific  information  when  such
information  is  available  for  use.   For  example,  a  user  can
incorporate  VMT mix,  mileage   accumulation,  and/or  registration
distributions  that  are  specific to  the  area  of   concern.   These
records are  all  optional, their use being dictated  by the values
of  some  of  the  flags  in  the   Control  section.    (Thus,   in  some
MOBILE4.1  runs  the  One-Time data  section will not be included in
the  input  sequence.)   If  any of these records are  included in the
input, they  follow  immediately after  the  Control  section and in
the order  in which they are discussed below.

     The One-time data  section  must be included if  one  or  more of
the following MOBILE4.1-options  are selected:

     1.  The user is  supplying  local tampering rates (TAMFLG = 2).

     2.  The user  is suppling  a VMT mix which will be applied to
         all emission factor calculations (VMFLAG = 3).

     3.  The user  is supplying  local mileage  accumulation and/or
         registration distributions by age  (MYMRFG  = 2, 3,  or 4).

     4.  The user  is  modifying the  basic  exhaust  emission rates
         used  in to calculate the  emission  factors  (NEWFLG  = 2).

     5.  The user  is  including an  Inspection/Maintenance  program
         in  the emission  factor  calculations (IMFLAG = 2).

     6.  The user  is  including an  anti-tamper ing program in the
         emission factor  calculations (ATPFLG = 2).

     7.  The  user  is  including the effects  of  Stage  II and/or
         onboard  vapor  recovery  systems   on  the  refueling  HC
         emission factors (RLFLAG  = 2, 3, or 4).

     8.  The user  is having  the  same  local area  parameter  (LAP)
         record  input values applied to all scenarios of a MOBILE4
         run (LOCFLG  =  2).

     9.  The user is supplying a single  set  of  values  on  trip
         length  distribution  to  be used   in  the  calculation of
         running loss emissions for all scenarios  (SPDFLG = 4).

Any data  in  the One-Time data  section  is listed  in the same  order
as  the order of the  associated  flags  in the Control data section.
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                               2-20

2.2.1  TAMPERING RATES

     2.2.1.1  Description

     MOBILE4.1  calculates tampering  rates  as  a piecewise  linear
function of  accumulated mileage  for  each  gasoline-fueled  vehicle
type  (LDGV,  LDGT1,  LDGT2,   and  HDGV)  and for  eight  types  of
tampering   [air   pump   disablement,   catalyst  removal,   overall
misfueling,   fuel   inlet  restrictor   disablement,    exhaust   gas
recirculation (EGR) system disablement,  evaporative  control  system
disablement,   positive   crankcase    ventilation    (PCV)    system
disablement, and missing gas caps].  These  rates are combined with
the  corresponding  fractions of  vehicles  equipped  with the  given
control technology  and the  emissions  impact rates  to obtain  the
tampering offsets (the  increase  in emissions that results from the
given type  of tampering).   These offsets are  later added to  the
non-tampered emission factors.

     2.2.1.2  Options

     MOBILE4.1  uses  tampering  rates  based on  QMS  analysis  of
multi-city   tampering   survey   results   if   no  locality-specific
alternate  rates  are supplied  as input  (TAMFLG =  1).  The use of
the rates included in MOBILE4.1 is recommended  for most situations.

     EPA  has  determined  through  its   tampering   surveys   that
tampering  rates  are lower in  areas  with  operating  inspection  and
maintenance  (I/M)  programs  than in  areas without  such  programs.
Provisions   exist  within  MOBILE4.1  for  the  input of  alternate
tampering  rates  (by setting  TAMFLG = 2).  Thus, if  TAMFLG  =  2  and
IMFLAG  =  1,  the  user  must  supply  one set  of  alternate  tampering
rates,  representing the case where  no I/M  program  is in  effect.
If  TAMFLG  = 2  and  IMFLAG = 2,   the user must  supply two  sets of
alternate rates, representing both the  non-I/M  and  I/M cases.  The
non-I/M rates are used to account for tampering that occurs before
the I/M program is operating.

     Before  approving  the use  of alternate  tampering  rates  in  the
development  of  base-year  highway  vehicle  emission  factors  and
mobile source emission  inventories, EPA  must review  and  approve of
the tampering survey(s) on which  such rates  are based.

     2.2.1.3  MOBILE4.1 Tampering Rates

     MOBILE4  uses  three  or  six  rate equations for each type of
tampering  stored within the model,  for each of the vehicle  types
subject to tampering (one each  for pre-1981 model  year  vehicles,
for  1981-83  model year vehicles,  and for  1984 and  later  model year
vehicles;  for  either  the  non-I/M  case only,  or  for  both  the
non-I/M  and  I/M  cases).   These  rate equations are based on  QMS
analysis of  national tampering survey data.
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                               2-21
2.2.1.4  Required Information

     The following information  is  required  for input  of  alternate
tampering rates:   For  each combination of  vehicle  type (pre-1981,
1981-83, 1984  and later model  year),  tampering type,  and  non-I/M
or  I/M  case,  you  must   supply  a  zero-mile  level  (ZML)  and
deterioration rate (DR; the rate of increase  in the tampering rate
per  10,000  miles  accumulated  mileage).   This deterioration rate
defines  the   increase  in  tampering   over   the   first   50,000
accumulated miles.   MOBILE4.1  adjusts these deterioration  rates
internally  to  account  for  the  rate  of  increase  in  tampering  at
mileages greater  than  50,000 mi.  All  tampering  rates are  assumed
to  stop increasing  after   130,000  accumulated miles.   All  input
values must be in fractional units.

     The order of the tampering types within each record is:

     1)  air pump disablement
     2)  catalyst removal
     3)  fuel inlet restrictor disablement
     4)  overall misfueling
     5)  EGR system disablement
     6)  evaporative control system disablement
     7)  PCV system disablement
     8)  missing gas caps.

     A complete set of alternate tampering  rate  input data  for the
non-I/M  case consists  of a total of 24 records, and a complete set
of  inputs   for  both  the non-I/M  and  I/M  cases   consists  of  48
records.   There are  six records  for  each  of the  four  gasoline-
fueled  vehicle  types  for   each case  (non-I/M,  I/M).    The  six
records  required  for  each  vehicle type  are listed  below.   Each
record  listed  occurs  four  times  (once  each  for  LDGVs,  LDGTls,
LDGT2s,  and HDGVs, in  that  order).
Non-I/M
 Case
Records

(  1- 4)
(  5- 8)
(  9-12)
 (13-16)
 (17-20)
 (21-24)
Non-I/M
and I/M
Records

( 1- 4)
( 5- 8)
( 9-12)
(13-16)
(17-20)
(21-24)
(25-28)
(29-32)
(33-36)
(37-40)
(41-44)
(45-48)
     Description
Format
ZML for pre-1981 MY vehicles
ZML for 1981-83 MY vehicles
ZML for 1984+ MY vehicles
ZML for pre-1981 MY vehicles
ZML for 1981-83 MY vehicles
ZML for 1984+ MY vehicles
DR for pre-1981 vehicles
DR for 1981-83 vehicles
DR for 1984+ MY vehicles
DR for pre-1981 MY vehicles
DR for 1981-83 MY vehicles
DR for 1984+ MY vehicles
(non-I/M)
(non-I/M)
(non-I/M)
(I/M)
(I/M)
(I/M)
(non-I/M)
(non-I/M)
(non-I/M)
(I/M)
(I/M)
(I/M)
8F8.4
8F8.4
8F8.4
8F8.4
8F8.4
8F8.4
8F9.5
8F9.5
8F9.5
8F9.5
8F9.5
8F9.5
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                               2-22

     2.2.1.5  Changes Since MOBILE4.1

     In terms of user  input to the model, the major change is that
when the user elects  to use alternate tampering  rates,  additional
equations are required.   This  is  due to the increase in model year
groups  (from  two  in  MOBILE4  to   three   here).    In  addition,
MOBILE4.1   adjusts   the   deterioration   rates   internally   for
accumulated  mileage  over   50,000   mi.    In  MOBILE4,   the  user
supplying  tampering  rate  equations  was  required  to  input  an
additional deterioration  rate  for  LDGVs  for mileages  over  50,000.
As  noted  above, MOBILE4.1  assumes  the  maximum  rate  of tampering
for  vehicles  of any  given  model  year is  the  rate occurring  at
130,000 accumulated miles.  This has no impact on the input data.

     2.2.1.6  Guidance

     The tampering rates built into  MOBILE4.1 are  the  rates that
should be used  in  all Clean Air Act  (CAA) mandated  development  of
mobile  source  emission  inventories.   Use of  any other tampering
rates in CAA-related work must be based on  actual in-use tampering
surveys, and the  surveys must be approved in  advance  by EPA.  For
guidance  regarding  EPA  approval   of  local   tampering  surveys,
contact the Office of Mobile Sources' Field Operations and Support
Division, 202/382-2633  or FTS  382-2633.   For  guidance  on analysis
of  the  data collected in  a local tampering  survey,  contact QMS'
Emission Control Technology Division, 313/668-4367 or FTS 374-8367.


2.2.2  VEHICLE MILES TRAVELLED MIX by vehicle  type

     2.2.2.1  Description

     The vehicle  miles travelled  (VMT) mix  specifies  the fraction
of  total  highway  VMT  that  is accumulated  by each  of  the eight
regulated vehicle  types.   The  VMT mix is used in MOBILE4.1 only to
calculate  the  composite   (all  vehicle,  or  fleetwide)  emission
factor  for a  given  scenario  on  the basis  of  the eight  vehicle
class-specific emission factors.

     2.2.2.2  Options

     You can choose between the use  of the  MOBILE4.1  national VMT
mix (by setting  VMFLAG  =  1),  the  input of one locality-specific
VMT mix for  use  in  all scenarios  of a given  MOBILE4.1  run  (by
setting VMFLAG  =3), or  the input  of a distinct locality-specific
VMT mix for each scenario (by setting VMFLAG = 2).

     For  highway   vehicle   emission  inventory  development,  EPA
generally  expects  States  to  develop and  use their  own specific
estimates  of  VMT  by  vehicle type.   In  such  cases, VMT fractions
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                               2-23

based  on  those  estimates  of  VMT  by  vehicle  type  should  be
calculated and used here as input.  A VMT mix used  as  input should
reflect they year for which emission factors are being calculated.

     2.2.2.3  MOBILE4.1 VMT Mix

     MOBILE4.1  calculates  a  typical  urban  area  VMT mix  based on
national data characterizing  registration  distributions  and annual
mileage  accumulation rates by age  for  each vehicle  type,  diesel
sales fractions by model year (for LDVs and  LDTs  only),  total HDDV
registrations  and  annual  mileage  accumulations  by weight  class,
the  fraction  of travel  by each  vehicle  type  that is  typical of
urban  areas,  and  total  vehicle  counts  (fleet  size)   by vehicle
type.  Considering the dependence of the calculated VMT  mix on the
annual  mileage  accumulation  rates and registration distributions
by age, the use of the MOBILE4 VMT mix  is  generally recommended in
cases where the focus  is on direct comparison of national or area-
wide emission factors under different assumptions.

     As  noted  above,   for   highway  vehicle  emission   inventory
development,  EPA expects  that States  will  generally develop  and
apply  their  own  estimates of  VMT by  vehicle  type for  specific
highway  facility  types,  sub-zones, times  of day,  and  so on.  The
use  of  an  alternate VMT mix  can result in  minor  inconsistencies;
for  example,  assumptions  that  are used  in  the  emission  factor
calculations concerning the gas/diesel  LDV  sales  fractions are not
altered  through the use of  different  VMT  fractions for LDGVs and
LDDVs.   In   part   for  this   reason,   MOBILE4.1   has   the  added
capability  for  the user to  also input a  locality-specific set of
gas/diesel LDV  and LDT sales  fractions  by  model year,  as  discussed
in section 2.3.10.

     However,  such  inconsistencies  will  not  significantly affect
emission inventory construction unless  the  inventory is  based  only
on the  fleetwide  composite emission factor and total mobile source
VMT.    Inventory  construction   based  on   vehicle-type-specific
emission factors  and VMT  estimates,  as EPA  expects of  States for
SIP-related  inventory  development, will   not  use the   composite
fleetwide emission factor.

     2.2.2.4  Recfuired Information

     Each VMT mix supplied as input must consist of a set of eight
fractional  values,  representing  the  fraction  of  total  mobile
source  VMT accumulated  by each  of  the eight  vehicle  types.  All
values  must  be between  zero  and one  (0.0  <^ VMT  fraction for any
vehicle  type   <_   1.0),  and  the  eight  values  must  sum to  1.0
(MOBILE4.1 produces  an error  message and does  not  execute the run
if these constraints are not  met).
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     The format  of the  VMT mix  record(s) is  8F4.3.   The  values
correspond to the  eight  vehicle  types in this order:   LDGV,  LDGT1,
LDGT2, HDGV,  LDDV,  LDDT,  HDDV,  and MC.

     2.2.2.5  Changes Since MOBILE4

     There have been no  revisions to how  an  alternate VMT  mix  is
supplied to the program as input data since the release of MOBILE4.

     2.2.2.6  Guidance

     States are  generally required to develop  estimates  of  VMT  by
vehicle type  for use  in  construction of  highway  vehicle emission
inventories for CAA-mandated and  SIP-related  purposes.   Given such
estimates of VMT by vehicle type, and  thus  of total  highway VMT,
it  is  straightforward  to calculate  a VMT mix  and that  mix should
be  used  as input  in  MOBILE4.1  runs.   Techniques  for  calculating
estimated VMT by vehicle type  (and thus, total VMT and the VMT mix
fractions) from  available data sources  are described in  Chapter 6
of the report, "Techniques for Estimating MOBILE2 Variables."*


2.2.3  ANNUAL MILEAGE ACCUMULATION RATES and/or REGISTRATION
       DISTRIBUTIONS by vehicle type and age

     2.2.3.1  Description

     MOBILE4.1's  emission  factor  calculations  rely  in part  on
travel fractions for vehicles of each given age and type, which in
turn   are  based  on  estimates  of  the  average  annual  mileage
accumulation  by  age  (first   year  to  25th-and-greater  years  of
operation)  for   each   of  the   eight   vehicle   types,   and  the
registration distribution by age (age 0-1 to age  24-25+)  for each
vehicle  type,   except  motorcycles,   for which  annual  mileage
accumulation   rates   and   registration  distributions   are  only
provided for  the first  to  12th-and-later  years of operation (ages
0-1  to 11-12+).   For  all vehicle  types except  motorcycles,  this
represents  an increase  from  the  20  years of  operation accounted
for  in MOBILE4.

     2.2.3.2  Options

     MOBILE4.1  uses national  average annual  mileage  accumulation
rates  by  age  and  registration  distributions  by age,  and  has
provisions allowing the  input  of  locality-specific data  for either
or  both of  these.   The use  of  the annual  mileage  accumulation
rates  by age included  in MOBILE4.1  is strongly recommended.   Users
may develop  registration distributions  by  age   on  the  basis  of
 *  See section 2.5  for  information on obtaining referenced reports
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locality-specific data,  and the States  are  strongly  encouraged to
do  so  in  developing  highway  vehicle  emission  inventories  in
response to the requirements of the new CAA for SIP purposes.

     2.2.3.3  MOBILE4 Annual Mileage Accumulation
              Rates and Registration Distributions

     If you do  not  provide  locality-specific  mileage accumulation
rates  and/or  registration  distributions  by  age,  MOBILE4.1  uses
national average values.

     This  information is  used for  all  calendar years  evaluated.
The  annual milege  accumulation  rates  are  based  on analyses  of
information  developed  over  a  long  period   of   time,   and  the
registration distributions  are based  on analysis  of  calendar year
1990 registration data.  Due to the  importance of  this information
in  characterizing  the in-use fleet, the need  to  avoid basing such
information on data collected over a short period  of  time (thereby
increasing the  risk  of reflecting atypical or cyclical use or sale
patterns),  and  the  inherent  difficulty  of  developing  accurate
locality-specific  data   describing  annual   mileage  accumulation
rates by age, the use  of  the MOBILE4.1 annual  mileage accumulation
rates by  age  is recommended.  The use of locality-specific data to
derive  registration  distributions by  age  is more  appropriate for
some  applications,   particularly   those  cases  where  such  data
reflect significant differences from the national average.

     If  local   annual  mileage  accumulation  rates  or registration
distributions  are used,  they  normally  should not  change across
calendar  years.  In  particular,  EPA  will not  accept SIP-related
modeling  that  includes assumptions that  the vehicle  fleet will be
newer (have  a  lower  average age)  in  the future than is reflected
in  the  registration  distributions used  for  the base year emission
factor  modeling and  inventory development.  Modeling that  assumes
no  further aging  of  the  fleet  from  the  current characterization
will be accepted by EPA for  SIP purposes.

     2.2.3.4  Required Information

     These  records  are required  if  MYMRFG  is  set  to  2,  3,  or   4
(see section 2.1.7).

     To use  locality-specific  annual  mileage accumulation rates by
age,  a  total  of 200  input values  are  required:    the  estimated
annual  mileage accumulated by vehicles  of each of  the eight  types
for  each  of  25 ages  (except 12 ages  for motorcycles; use  ".00000"
as  the  annual  mileage accumulation rate for motorcycles of  ages 13
through 25).   These  values  are  input  as miles  divided  by  100,000
(e.g.,  12,637 miles  is input as 0.12637).
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     To use  locality-specific registration  distributions by  age,
again a total  of  200 input values are required.   For  each vehicle
type, a set  of 25  values  (except 12 values  for  motorcycles;  use
".000" as  the  registration  distribution fraction  for  motorcycles
of ages 13 through  25)  are required  to  represent the  fraction of
all  vehicles  of  the given type  that are of  a given  age.   These
registration distributions should  be  based on  July 1  of  the  year
being  modeled;  MOBILE4.1,  as previous  versions  of  the  model,
converts this distribution to a January 1 distribution.

     Any individual  value  must be between zero and one.  The sum
of the  registration distribution values  for  a given vehicle  type
must  equal  1.0;  if they  do  not, MOBILE4.1  normalizes  the  input
values so that  the  sum for each vehicle type  is  equal  to 1.0, and
a  warning  message   is  produced  for  each  occurrence.   The  same
registration  distribution  by  age must  be entered for  LDGVs  and
LDDVs,  and  for  LDGTls  and  LDDTs.   MOBILE4.1 uses  an  internal
function to  separate  these  pairs of  vehicle  types into distinct
gas  and diesel distributions, based  on  diesel sales  fractions by
model year.   (For  information on user  input  of  alternate  diesel
sales  fractions  by model  year,   see section 2.3.10.)   If  this
constraint is  not met,  the error  message(s)  M65 and/or M66 will be
produced (see Chapter 3), and the MOBILE4.1 run will not execute.

      In addition,   in  the  case where you supply  both  the  annual
mileage   accumulation   rates  by   age   and   the   registration
distributions  by   age,   the   annual  mileage   accumulation  rate
corresponding to  any vehicle  type/age combination accounting for a
non-zero  fraction  of  registrations  must be   positive   (i.e.,  if
vehicles of  a certain type  and age exist in  the  fleet,  then they
must  accumulate some  mileage).   If  this  constraint  is  not  met,
MOBILE4.1 will generate one  or  more error  messages  and the run
will  not be executed.

      The  annual  mileage  accumulation  rates   are  entered  as  24
records, in sets  of three  records per vehicle type.  The format of
these  records  is  (10F7.5,  10F7.5,.  5F7.5),  repeated eight  times.
Registration distributions  by age are also entered as  24 records,
in  sets  of three  records  per vehicle  type  of   format   (10F5.3,,
10F5.3,  5F5.3).   If both  annual mileage  accumulation  rates and
registration  distributions are being supplied by  the  user,  the
annual  mileage  accumulation  rates  precede   the   registration
distributions  [24 records, format  (10F7.5, 10F7.5, 5F7.5) repeated
eight  times,   followed  by 24 records,   format  (10F5.3,,  10F5.3,
5F5.3) repeated eight times].

      In both  cases,  the 24  records  represent  three   records  per
vehicle type  for  each of eight vehicle types in this order:   LDGV,
LDGT1, LDGT2,  HDGV, LDDV,  LDDT,  HDDV, and MC.   Each of  the three
records per  vehicle type  contains  the  annual  mileage  accumulation
rate  by age, or the registration distribution by age, as follows:
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     First record  -   age 1,   age 2,   age 3,  .  .  .  ,  age 10
     Second record -  age 11,  age 12,  age 13,  .  .  .  ,  age 20
     Third record  -  age 21,  age 22,  age 23,  age  24,  age 25.

     2.2.3.5  Changes Since MOBILE4

     The  changes  required  for  the user  input of  annual  mileage
accumulation  rates   and/or  registration  distributions   by  age
consist of the  necessity of supplying  three  records (up  from two
in MOBILE4)  for each parameter for each  vehicle  type.   The format
of the individual records is the same, with the exception that the
third  record for  each  parameter  for  each  vehicle  type  contains
five, rather than ten, values.

     2.2.3.6  Guidance

     For  most users in  most  applications,  the use  of  the annual
mileage   accumulation  rates  by   age  included  in  MOBILE4.1  is
recommended.  Most  local sources of  mileage  accumulation  rate  by
age  data  are subject  to sampling bias  or  data  entry  errors, and
the use of such data should be  approached with  caution.   States in
their  development  of  highway  vehicle  emission  inventories  in
response  to  the requirements of  the  new CAA  should obtain  prior
approval  of   alternate   mileage  accumulation   rates   and  their
derivation  from EPA  before  using such  rates in  their  emission
factor modeling.

     The  use  of  locality-specific   data to  derive  registration
distributions by age  is more  appropriate  for many  applications,
particularly  those  cases  where  such  data  reflect  significant
differences  from   the   national   average.    EPA  encourages  and
recommends  the  use of actual  locality-specific calendar year 1990
registration  distributions  by  age  in  the  development  of  SIP
emission  inventories.  One  exception  to this would be areas having
relatively   few   local    HDDV    registrations,   but   significant
interstate  trucking activity within  the  local  area.   Such   areas
may  want  to  retain and  use  the  MOBILE4.1  national  registration
distributions.    EPA  will   issue  additional   guidance   on  how
locality-specific calendar  year 1990  registration distributions by
age may be adjusted to reflect  future years at a later date.

     In many situations, registration  distributions  by age may be
developed  from  data   available  through   State  motor   vehicle
registration   records.    Especially    when   such   data   reflect
registration  distributions that  are  substantially different from
the  national average, such distributions should be  developed and
used.   In  particular,   the  States in  preparing highway  vehicle
emission  inventories in  response to  the requirements  of  the new
CAA  should  obtain  the  data  necessary to   develop  State-  or
locality-specific   registration   distributions,    as   applicable,
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subject to  the caveat in  the  preceding paragraph.   Note that  in
MOBILE4.1,  it  is  necessary to  develop such data for  the 25 model
years ending with the calendar year of  evaluation,  rather than the
20 years of data required for MOBILE4.

     If  local  annual  mileage  accumulation  rates  or  registration
distributions  are  used,   they  normally should  not change  across
calendar  years.   In  particular,  EPA  will  not  accept SIP-related
modeling that  includes assumptions  that the vehicle fleet will  be
newer  (have a  lower  average  age)  in  the future than  is reflected
in the  registration  distributions  used for  the  base year emission
factor   modeling   and   inventory  development.    The   use   of
registration distributions  that indicates that  the vehicle fleet
is newer  than  that  reflected  in the  MOBILE4.1  distributions will
only be accepted  if  the area  supplies adequate documentation  to
support  this assumption.  Modeling  that assumes no  further aging
of the  fleet from the current  (base year) characterization will  be
accepted by EPA for SIP  inventory purposes.

     Methods for  estimating the annual mileage  accumulation rates
by age  and  the registration distributions by vehicle  type  and age
are  presented  in  Chapters 2  and  3,  respectively,  of  the  report
"Techniques for Estimating MOBILE2 Variables."


2.2.4   BASIC EMiSSION RATES

     2.2.4.1  Description

     The  basic emission  rates  (BERs)  in MOBILE4.1 are expressed in
the  form of linear  equations, consisting  of  a  zero-mile level
(ZML),  or y-intercept, and one or two  deterioration rates (DR), or
slopes   (increase   in  emissions  per   10,000   miles   accumulated
mileage).   The units used for  all  vehicle  types except  heavy-duty
vehicles  (HDGV, HDDV)  are grams per mile  (g/mi) for  the ZMLs and
g/mi  per 10,000 miles  (g/mi-lOK mi)  for the DRs.   For  HDGVs and
HDDVs,  the  units  are grams  per brake  horsepower-hour (g/BHP-hr).
There  are  different  BER equations  in MOBILE4.1 for  each vehicle
type/pollutant/model  year  group,  with the model  year  groups
defined on  the basis of  applicable emission standards and emission
control technologies used.

     For   light-duty  gas  vehicles   (LDGVs),   there   are   two
deterioration  rates  in each  BER  equation.   In   each  such" BER
equation,   there  one  DR  is  applicable  to  mileage  accumulated
between  zero  and   50,000  miles,  and  a  second  (higher)   DR  is
applicable   to  mileage  accumulated   beyond  50,000  miles.   This
feature is  applicable only to LDGVs.
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     2.2.4.2  Options

     MOBILE4.1  provides  the  capability  to  input  alternate  HER
equations (by setting NEWFLG = 2).  However, the BERs  in MOBILE4.1
accurately  reflect  all promulgated emission  standards as  of  late
1990,  and  no  locality-specific  changes  to  these  equations  are
warranted for  use  in  developing  emission  factors or  inventories
for calendar years  through  1992,  or  for CO projection inventories
through  calendar  year  1996  (as  noted  below).   This  specifically
includes the development of base  year 1990  emission  inventories by
the States  in response to  the requirements of the Clean Air  Act.
The  option  of  alternate  BERs  is intended for  use  only in  the
situation where new or revised emission  standards are promulgated
by EPA  after  release  of  MOBILE4.1.   As noted  in section 1.1.12,
the carbon  monoxide (CO)  and "cold CO"  emission standards mandated
by the  new CAA  for  LDVs  and LDTs  are reflected  in  MOBILE4.1,
allowing  MOBILE4.1  to be  used  to  project CO   emission  factors
through  1996.   Other new  emission standards and test  requirements
(which will affect  the BERs corresponding to a given standard) are
not included here.

     2.2.4.3  MOBILE4.1 Basic Emission Rates

     The  BER  equations in  MOBILE4.1  are based  on the  applicable
Federal  emission  standards  and the emission control  technologies
characterizing  the  fleet  in  various   model  years  (for  example,
different types of  catalytic  converters exhibit different rates of
deterioration).   These  equations  are  applicable  for  all  non-
California  areas,  both low-  and  high-altitude,  and should  not be
altered  by  the user without EPA guidance.

     2.2.4.4  Required Information

     If  alternate BER equations  are  to be used,  the information
that  must  be  supplied  includes:   the  number of  alternate  BER
equations  that are to  be  entered,  the  region  (low-  or  high-
altitude) to  which the alternate BERs  apply, the vehicle type(s)
affected, the  first and last  model years for which the alternate
equations apply, the ZML (g/mi),  and the DR (g/mi per 10K mi).

     If  the vehicle type  affected is LDGVs,then  two deterioration
rates must  be supplied.   The first is  used to  calculate emissions
deterioration  through  50,000  accumulated  miles,   and  the  second
(higher)  rate  is  applied  to accumulated mileage beyond  50,000 mi.
If  the  vehicle type affected is  HDGV  or HDDV, units  of g/BHP-hr
must be  used  for  the  ZML and  units  of (g/BHP-hr)/IOK  mi  must be
used for the  DR,  since MOBILE4.1 converts g/BHP-hr rates to g/mi
rates internally.
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     The new  BER  input consists  of a  set of  N+1  records,  where
N  is  the  number  of  new BERs  (records)  that  follow  the  first
record.  The maximum number  of new BERs  permitted in a  MOBILE4.1
run  is  100.   In addition, for  each combination  of  region/vehicle
type/pollutant,  no  more  than  12   new  BERs  are  permitted.   The
format  specifications,  allowable  ranges,  and  codes  for  these
records are summarized in Table 2.2-1.

     2.2.4.5  Changes Since MOBILE4

     There have been no revisions to the content  or format  of user
input alternate BERs since the release of MOBILE4.

     2.2.4.6  Guidance

     No need  exists  for modification of  the BERs  in  MOBILE4. l in
order  to  develop  emission  factors  for  any  pollutant  for  any
calendar year through  1992 inclusive,  or  for CO  emission  factors
for  any calendar  year  through  1996  inclusive.   EPA expects  to
release  another model  update that will  incorporate all  of  the
requirements of the November 1990 CAA in time for States  to use in
projection year modeling.   If the .use  of alternate BER equations
in MOBILE4.1  is being contemplated,  the  Office of Mobile  Sources
(Test  and  Evaluation Branch,  313/668-4325 or FTS 374-8325) should
be contacted for additional guidance.


2.2.5   INSPECTION AND MAINTENANCE PROGRAMS

     2.2.5.1  Description

     Many  areas of  the  country have  implemented inspection  and
maintenance  (I/M)  programs as a  means  of further  reducing mobile
source  air pollution.    MOBILE4.1  has  the capability of  modeling
the  impact of an  operating I/M program on the  calculated emission
factors,   based  on  user  specification   of  certain  parameters
describing the program to be modeled.

     2.2.5.2  Options

     The user has  the  option  of  either accounting  for the  effects
of  an  I/M  program (by  setting  IMFLAG =  2),  or of  assuming that
there  is  no I/M  program  in  effect  (by  setting IMFLAG  =  1).
Standard   low-altitude   area   emission   reduction   credits  are
contained  in the  MOBILE4.1 code,  and standard  high-altitude area
emission credits  are included as a separate  file on  the MOBILE4.1
diskettes  and  tapes.   The  model  is  also   capable  of  accepting
alternate credit matrices developed by EPA as input data.
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     2.2.5.3  Required Information

     If  IMFLAG  = 2,  all of  the  following I/M program  parameters
must be specified by the user in the order shown:

     o        Program  start  year   (calendar  year   that  program
              begins)

     o        Stringency level (percent)

     o        First  (earliest)  and  last  (latest)  model years  of
              vehicles subject to the requirements of the program

     o        Waiver rates  (percent  of  failed  vehicles; one  rate
              applicable to  pre-model  year  1981  vehicles  and one
              applicable to 1981 and later model year vehicles)

     o        Compliance rate (percent)

     o        Program   type    (centralized;    decentralized   and
              computerized; or decentralized and manual)

     o        Frequency of inspection (annual or biennial)

     o        Whether  or  not each  of four possible  vehicle types
              (LDGV, LDGT1, LDGT2, HDGV) are covered by the program

     o        Test type (idle, 2500/idle, loaded/idle)

     o        Whether  or  not  alternate  I/M  credits  are  to  be
              supplied  for  each  of  two  technology groups  (Tech
              I-II, Tech IV+)

     The format of this record is:

     4 ( 12 , IX) , 2 (F2 . 0 , IX) , F3 . 0 , IX, 2 ( 11, IX) , 411, IX, 11, IX, 211

     Table  2.2-2  summarizes  the  I/M  descriptive  input  record
required  if IMFLAG =  2,  including the  codes  and allowable values
for each field of the record.  See Appendix 2A  to  this chapter for
more detailed discussion of each of the parameters listed above.

     2.2.5.4  Changes Since MOBILE4

     There  have  been no revisions  to the  information  required to
model the benefits  of  I/M programs, or  to  the  format requirements
of this record, since the release of MOBILE4.
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     2.2.5.5  Guidance

     Additional  information  on   the   modeling  of   I/M   program
benefits in MOBILE4.1  is  provided in Appendix 2A.   For those cases
where  the  emission   reduction  credit  matrices   included  with
MOBILE4.1  are inappropriate  for  the   I/M  program  being  modeled,
contact  the  Office of Mobile  Sources  (Technical   Support  Staff,
313/668-4367 or FTS 374-8367) to obtain the required matrices.


2.2.6  ANT I-TAMPER ING PROGRAMS

     2.2.6.1  Description

     Some  areas  of  the  country  have  implemented  anti-tampering
programs  (ATPs)  to  reduce  the  frequency  and  resulting  emission
impact of emission control tampering  (e.g.,  misfueling,  removal or
disablement  of catalytic  converters).   MOBILE4.1 allows  the  user
to  include  the  effects   of  such a  program  on  the  calculated
emission factors.

     2.2.6.2  Options

     You can  choose to model the  effects of an ATP on the emission
factors  (by  setting ATPFLG = 2),  or to  assume  that no ATP is in
effect  (by setting ATPFLG =  1).   The  information  required of the
user  if ATPFLG  =  2   is  discussed  below.   MOBILE4.1  contains  a
subroutine  that  will  generate   the   applicable  emission  factor
credit matrices  based  on the information that you  provide  on the
characteristics of the ATP.

     2.2.6.3  Required Information

     The following must  be specified by  the user  in order to have
MOBILE4.1 model the effects of  an  ATP,  in the order  shown:

     o         Start  year  (calendar  year  in  which  the  program
              begins)

     o        First (earliest)  and last  (most  recent) model years
               of vehicles  subject  to the program

     o        Whether  or  not each of  four possible  vehicle types
               (LDGV, LDGTl, LDGT2, HDGV)  are covered by the program

     o         Program  type (centralized or decentralized)

     o         Frequency of inspection  (annual or biennial)

     o         Compliance  rate (percent)
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                               2-33

     o        Inspections performed  (air  system,  catalyst,  fuel
              inlet restrictor,  tailpipe  lead deposit  test,  EGR
              system,  evaporative system,  PCV,  gas cap)

     The format of this record is:

              3(12,IX),411,IX,II,IX,211,IX,F4.0,IX,811.

     Table  2.2-3  summarizes  the  ATP  descriptive  input  record
required if ATPFLG =  2,  including the variable  names,  codes,  and
allowable values  for  each field of  the record.   See Appendix  2A
for more detailed discussion of each of these parameters.

     2.2.6.4  Changes  Since MOBILE4

     There have  been  no revisions to  the information  required  to
model ATP  effects, or  to the  format requirements  of  that  data,
since the release of MOBILE4.

     However,  MOBILE4.1 will  only  model  an ATP with an evaporative
system inspection (sixth in the  list of  inspections  performed)  and
provide appropriate emission  credits  if  a gas cap inspection (last
in the  list of  inspections  performed)  is also  included.    If  the
user indicates  that an evaporative system inspection is performed,
but that a  gas  cap inspection  is  not  performed,   an  error message
will be  issued and execution  of the run will  stop.   The  converse
is not true:  It is allowable to have a gas  cap inspection without
having an evaporative system inspection.

     2.2.6.5  Guidance

     Additional   information   on  the  modeling   of   ATP   program
benefits in MOBILE4 is provided in Appendix 2A.   Further  guidance
on  developing  the information required  to  model   the emissions
impact  of  an  ATP can  be  obtained  by  contacting  the Office  of
Mobile  Sources  (Technical  Support  Staff,   313/668-4367  or  FTS
382-8367).


2.2.7  REFUELING EMISSIONS

     2.2.7.1  Description

     The  refueling  of  gasoline-fueled  vehicles results   in  the
displacement  of  fuel  vapor  from the  vehicle  fuel  tank  to  the
atmosphere.   There are two  basic approaches  to  the  control  of
vehicle  refueling emissions, generally referred  to  as  "Stage  II"
(at  the  pump)  and  "onboard"  (on  the  vehicle)  vapor  recovery
systems  (VRS).   MOBILE4.1  has  the  ability  to model uncontrolled
levels  of  refueling emissions  (i.e.,  assuming no requirements for
Stage  II or  onboard   VRS  systems),  as well  the  impacts  of  the
implementation  of either or both of the major types of VRS.
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     2.2.7.2  Options

     There  are  five approaches  available  in MOBILE4.1  for  the
modeling  of  vehicle refueling  emissions,  depending  on the  value
assigned to RLFLAG:

       Value     Action
         1     Model  uncontrolled  refueling   emissions   for  all
               gasoline-fueled vehicle types
         2     Model  refueling  emissions  assuming  a Stage  II  VRS
               requirement
         3     Model  refueling  emissions  assuming  an  onboard  VRS
               requirement
         4     Model  refueling  emissions  assuming  both  Stage  II
               and onboard VRS requirements
         5     Account  for refueling  emissions  elsewhere   in  the
               inventory; no  refueling  emission factors calculated
               by MOBILE4.1

     There  are  no additional input  requirements for the  first  or
last approaches.   If  you wish to include the effects of  either  or
both  VRS  requirements   on refueling  emissions, you  must  supply
certain information to be assumed about the program.

     2.2.7.3  Refueling Emissions in MOBILE4.1

     The uncontrolled refueling  emission factors in MOBILE4.1  are
based  on  vehicle  test  results  which  were  used  to develop  a
regression  equation  expressing  refueling  emissions as a  function
of  fuel RVP,  temperature  of dispensed  fuel,  and  difference  in
temperatures of  dispensed and residual  tank fuel.    Each  of these
values  is  supplied by  the model user, either  directly (fuel RVP)
or indirectly (the temperature of the dispensed fuel is a function
of the  input minimum and maximum temperatures, while the "delta T"
temperature  term  is  a  function  of  the  dispensed temperature).
This  equation yields  refueling  EFs  in  terms  of   grams  of vapor
emitted per gallon of  fuel  dispensed  (g/gal).   To this  value  is
added  an  estimate  of spillage  losses,  also  in g/gal.  Combining
this total  g/gal emission  factor with  vehicle fuel  economy data
(mi/gal)  yields  refueling  emission  factors  in  grams  per  mile
(g/mi).

     If you wish to model the effect of  a  Stage II  VRS requirement
on these  emissions,  its in-use control efficiencies  (for LDGVs and
LDGTs,  and for  HDGVs)   must  be  entered  as input.  There  are  no
national  average values for  Stage  II  efficiency in MOBILE4.1.   In
modeling  an  an  onboard  VRS  requirement,  MOBILE4.1  assumes  a
96 percent   reduction   from  uncontrolled  levels   in  refueling
emissions from onboard-equipped vehicles.
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     2.2.7.4  Required Information

     To model the effect  of  a Stage  II  VRS requirement, you  must
provide four  inputs:   the start  year (calendar year  in which the
requirement takes  effect),  the  phase-in period  (number of  years
for  Stage  II VRS  installation to  be completed),  and  the  system
efficiency  (in  percent)  at  controlling  refueling  emissions  from
light-duty vehicles and trucks, and from heavy-duty vehicles.

     Modeling the  effect of  an  onboard  VRS requirement  requires
the user to provide  only the  starting model year and  which  of the
four possible vehicle  types (LDGV,  LDGT1, LDGT2,  HDGV) are subject
to  the requirement.   The effects  of  the  EPA reproposal  for  a
national onboard VRS requirement, as  mandated  by the  CAA,  can be
modeled if  necessary  by verifying the  specifics  of  the  program
with EPA (see section 2.2.7.6).

     All of  the above information must  be supplied  if both VRS
requirements are assumed.

     The format of the Stage II VRS descriptive record is:
     The format of the onboard VRS descriptive record is:

           12, IX, 411.

     If both  records  are to be supplied, the Stage  II  descriptive
record  precedes  the  onboard  descriptive  record.    Table  2.2-4
summarizes both  of  these possible records,  including  the variable
names, codes, and allowable values for each field.

     2.2.7.5  Changes Since MOBILE4

     There have  been no  revisions  to the  information  required to
model the effects of either type  of VRS  on refueling emissions, or
to  the  format requirements of  that  information,  since the release
of MOBILE4.

     2.2.7.6  Guidance

     EPA recommends  that States and others use MOBILE4 . 1  to model
refueling   emissions  for   highway  vehicle   emission  inventory
development.  The  refueling emission factors can  be calculated in
grams  per  gallon  of dispensed fuel  (g/gal)  or in  grams  per mile
(g/mi).   The preferred  approach is  to  calculate g/gal refueling
emission  factors  using  MOBILE4.1,  reflecting  Stage  II  and/or
onboard VRS requirements  as  applicable,  then multiplying the g/gal
emission  factor  by  total  gasoline  sales.   This  is  the  most
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accurate  method  of  estimating   the   contribution   of  refueling
emissions to  the  inventory,  particularly for areas  with  good data
on gasoline  sales  (e.g.,  through  tax  records).   This  method also
accounts  for  refueling  emissions  generated   when  gasoline  is
purchased in  an  area, but consumed  largely outside of  the  area,
and does  not include refueling emissions for through traffic that
does not  refuel in  the  area.   When good data on  gasoline sales is
not available,  the use  of the g/mi  refueling emission  factor is
more convenient and,  while also more  approximate,   acceptable  for
SIP inventory development.

     The  overall   effectiveness  of  Stage  II  VRS   at  controlling
refueling emissions depends on a number of  factors,  including the
baseline  efficiency  of  the system used, the portion of total area
gasoline  consumption  handled  by  service   stations  exempt  from
Stage II  requirements,  and   the  frequency  and   stringency  of
enforcement programs.   In  general, the  effectiveness of  Stage II
VRS at  controlling refueling emissions will be  greater for light-
duty vehicles and trucks than for  heavy-duty vehicles,  since HDGVs
are more  likely to be refueled at service  stations  (or other fuel
dispensing locations, such as  private  refueling  depots)  that will
be  exempted  from   Stage   II   requirements.    For  assistance  in
developing such  information,  contact EPA's Office  of  Air Quality
Planning  and Standards (919/541-5397 or FTS  629-5397).

     Since  any  onboard  requirement would  be  a national control
program,  the  only  issues are  what model year  the program will be
implemented  and  whether or not  all gasoline-fueled vehicles will
be  covered.   The  Clean  Air  Act   Amendments  of  1990  provide  the
manufacturers with a three-year  phase-in  period when EPA issues
onboard   VRS  regulations.    This  phase-in  is  not  reflected  in
MOBILE4.1; it will be included in the next model update.

     If  the  user  chooses  not to  model refueling  emissions using
MOBILE4  (by  setting  RLFLAG  =  5), then  these  emissions  must be
accounted for in  the stationary  source portion of the  inventory in
the development  of  the  base  and  projected emission  inventories.
The effects  of  an onboard  VRS system requirement cannot be modeled
if this  approach  is taken.   EPA recommends  that  States and others
use  MOBILE4.1 to  model  refueling emissions  for highway vehicle
emission  inventory development.


2.2.8  LOCAL AREA PARAMETER RECORD

     2.2.8.1  Description

     The  local  area parameter  (LAP)  record  consists of six, seven,
or  eight locality-specific input  variables.   This   record  must be
included  at least once in every MOBILE4.1 run.
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     2.2.8.2  Options

     You can  choose  to use  one  LAP for  all  scenarios of  the  run
(by setting LOCFLG = 2)  or  a different LAP for  each  scenario  (by
setting LOCFLG =  1).  With the possible exception of  the  scenario
name  (see  section 2.2.9),  the same LAP  generally should  be  used
for all scenarios  (e.g.,  different evaluation  years)   for  the  same
locality.

     2.2.8.3  Content of the LAP

     The following variables comprise the LAP record:

           1)     Scenario name
           2)     Minimum daily temperature
           3)     Maximum daily temperature
           4)     Base (pre-control) RVP
           5)     In-use (controlled) RVP
           6)     In-use RVP start year
           7)  *  OXYFLG
           8)  *  DSFLAG

     The   last   two  variables,   indicated   by  asterisks,   are
optional.    Each  variable  is discussed  in sections 2.2.9 through
2.2.15  below.   Table  2.2-5  summarizes the LAP  record,  including
the content,  variable name,  codes,  and allowable values  for  each
field of the record.

     2.2.8.4  Changes Since MOBILE4

     There have been three revisions to the LAP  records  since the
release of  MOBILE4.   First,  the ASTM  volatility class,  which used
to  be the  second variable  specified  on  the  LAP  record, is  no
longer  used in MOBILE4.1  and is no longer required  as  input (see
section 2.2.10).  The second and third  changes  are the addition of
two  optional   flag values  at the  end of  the  LAP record.  These
flags  indicate whether  the  user  wishes  to model the  effects  on
exhaust  CO emissions of  oxygenated fuels,  and whether  the  user
wishes  to supply  alternate  diesel  sales  fractions  for  LDVs  and
LDTs  as input data.  These  flags  are  discussed in sections 2.2.14
and 2.2.15 respectively.


2.2.9  SCENARIO NAME

     2.2.9.1  Description

     A  field  of  16  character spaces is  available for entering an
identifying label  for each  scenario within a  run.  This  label is
echoed  as  part  of the output.  Nothing about the  scenario  name and
its use has been  revised since the release  of MOBILE4.
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     2.2.9.2  Guidance

     If no scenario name is desired, a blank field must  be entered
here.  This  field is typically  used to define  the  most important
characteristics distinguishing the  scenario from others  within the
same  MOBILE4.1 run  (e.g.,  calendar year of  evaluation, with  or
without an operating I/M program).


2.2.10  ASTM VOLATILITY CLASS

     2.2.10.1  Description

     This  variable,  which  represented  the  gasoline  volatility
class assigned to  a  given area for  a  given  month by  the American
Society   for  Testing  and  Materials,   is   no  longer   used  in
MOBILE4.1.   In order  to  minimize  the  need  for reformatting  of
input data  files  prepared  for  use with MOBILE4, the  space within
the LAP record that formerly contained the ASTM  class  remains, but
it  can be   left  blank.   If  a  letter  representing  ASTM  class  is
present,  MOBILE4.1  will not read  the letter  and it will have  no
impact on the execution of the program.

     2.2.10.2  Options

     Either  a  value (e.g.,  from a MOBILE4 input file)  or a blank
space  must  appear   in  order  to  maintain the   positions  of  the
remaining variables  on  the LAP record.  In any  case,  it will have
no impact on the execution of the program or its results.


2.2.11  MINIMUM and MAXIMUM DAILY TEMPERATURE

     2.2.11.1  Description

     The  minimum  and maximum daily temperatures are used directly
in  MOBILE4.1  in  the  calculation  of   the   diurnal   portion  of
evaporative  HC emissions,  and  in  estimating the  temperature  of
dispensed fuel for  use  in the calculation of  refueling emissions.
The  temperatures  used  in calculating  the  temperature corrections
to  exhaust  HC, CO,  and  NOx emissions,  the  hot  soak  portion  of
evaporative  emissions,  and  resting  loss  and  running  loss  HC
emissions  are calculated  by MOBILE4.1  based  on the  minimum and
maximum  temperatures  input here,  unless overridden  by  the user
(see sections  2.1.14 and 2.3.4).

     2.2.11.2  Options

     The  user  must  input  values  for  the  minimum  and  maximum
ambient temperatures.   The minimum temperature must be between 0°F
and  100°F  (-18°  to 38°C),  and the maximum  temperature must  be
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between  10°F and  120°F  (-12°  to  49°C)  inclusive.   The  maximum
temperature  must  be   greater  than  or  equal  to   the   minimum
temperature.

     2.2.11.3  Use in MOBILE4.1

     Diurnal  emissions   are  most   frequently  measured  for  the
Federal  Test  Procedure (FTP) temperature  range of 60°F  (16°C)  to
84°F  (29°C),  but diurnal emissions  in MOBILE4.1 are  adjusted for
the minimum and maximum  temperatures  provided  as  input based  on
testing  over  other temperature  ranges.   The basic exhaust emission
rates  for  HC,  CO,   and  NOx  are  based  on  the  standard  test
temperature  of  75°F.   MOBILE4.1  can  calculate a temperature for
each  pollutant  representing average emissions  over  the course  of
the day  (based  on  the input minimum and maximum daily temperatures
and a representative curve of temperature as a  function  of  time of
day),  and  adjusts  the  exhaust emission  factors for temperature
effects  accordingly.

     Hot  soak   emissions  at   FTP  conditions  are   based   on  a
temperature of  82°F  (28°C).  MOBILE4.1 can calculate a temperature
for  the  hot  soak  emissions,   based on  the minimum  and  maximum
temperatures  input  here,  and  adjust  the  basic hot  soak  emission
rates  for  temperature   effects  accordingly.    Resting  loss  and
running  loss  HC emissions  are  also dependent  on  temperature.  As
in  the  cases  of exhaust  and   hot   soak  emissions,  MOBILE4.1 can
calculate  appropriate average  temperatures for use  in  estimating
resting  loss  and running  loss  emissions,  weighted to account for
differing  emission  levels  at  different temperatures  in  the  range
of the minimum  and maximum daily temperatures.

     The model  should  be operated  in  this  mode  if the  desired
result   is  total daily  emissions  (emission  factors  representing
entire   days).   The  algorithm  used   in  MOBILE4.1  to  determine
temperatures  for correction of  the above types of emissions on the
basis  of the  input  minimum and  maximum  temperatures takes  into
account  both  the typical 24-hour  diurnal temperature profile  for a
day  having  the specified  minimum  and maximum,  and the  typical
distribution  of travel  over  the  course  of  24 hours.   Thus the
emission factors calculated  in  this  way are appropriately weighted
for  both trips and  emissions  at  different temperatures,  resulting
in factors  that can be  multiplied  by daily vehicle miles travelled
(VMT) when  total daily emissions are the desired result.

     The input value  of ambient  temperature  can also be  used to
determine the temperature corrections for exhaust HC, CO,  and NOx
emissions,   hot   soak   evaporative  emissions,  dispensed  fuel
temperature in  the refueling  emissions calculations,  and  resting
loss  and running  loss  emissions,  through the use of the  control
flag  TEMFLG (see section 2.1.14).   This is  not recommended unless
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the modeling  of  a  short time  period,  such  as  an hour,  is  being
performed.  Refueling emissions should always be modeled using the
"full  day"  approach,   not   with   hourly  temperatures.   Diurnal
emissions can only be  modeled by the "full  day"  approach, as the
algorithm used  is inaccurate  over  the very small  temperature  rises
(1 to 5 F°) typical  of a single hour.

     If  the  input  minimum   temperature  or  calculated  hot   soak
temperature is  <  40°F  (4°C),  evaporative  emission factors will not
be  calculated.   EPA  does not  have  sufficient data  to  estimate
evaporative emissions  at low temperatures, and there  is reason to
believe  that  such emissions  approach zero  when temperatures are
sufficiently  low.   The  MOBILE4.1   output will  include  a  warning
message   noting  the    lack   of   evaporative   emission   factor
calculations if  either of these temperature  conditions  occur.  If
the calculated running loss temperature  is <.  40°F,  no  running loss
emission   factors  will   be  calculated  for  similar  reasons.
Refueling  emissions  will  be  calculated  for   any  valid   input
temperatures.     Finally,   if  the   calculated  exhaust  emission
correction  temperature  is   <_ 45°F  (7°C),  the  exhaust  emission
factors  will  not be corrected  for  the  effects of  fuel  volatility
(RVP).

     2.2.11.4  Required Information

     Minimum and maximum daily temperatures (°F).

     2.2.11.5  Changes Since MOBILE4

     There  have been no  revisions  to the  temperature  input  data
requirements since the release of MOBILE4.

     2.2.11.6  Guidance

     The  temperatures  to be used  here  depend  on  the  intended
application . of  the  results.   Restrictions  on these  temperatures
are:  the  maximum temperature must be greater than or equal to the
minimum temperature, and the  ambient  temperature  should  be between
the minimum and maximum  (minimum  <_ ambient  <.  maximum) .  Guidance
on  the  determination  of  appropriate  temperatures  for  use  in
development  of  emission  inventories    for   nonattainment   areas
appears   in  "Procedures  for   Emission   Inventory  Preparation,
Vol. IV:  Mobile Sources," EPA-450/4-81-026d  (revised), July 1991.


2.2.12   "PERIOD 1" RVP

     2.2.12.1  Description

     Evaporative  and  refueling  emissions (and exhaust  emissions,
to  a  lesser  extent)  vary  with  fuel volatility.   EPA's  vehicle
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certification program and much  of  its emission factor  testing  use
gasoline  with  volatility  (as   measured  by  Reid  vapor  pressure
(RVP))  of 9.0 psi.   MOBILE4.1   adjusts  the  emission  factors  to
account for the effects of fuel  with other  than 9.0 psi RVP.

     The value to  be  used for "period 1" RVP is the average in-use
RVP of  gasoline  in the  area  to be  modeled  in the  time before  a
volatility control  program  takes effect,  or the years  preceding a
change  in  the controlled RVP level  (such  as will  occur in  most
areas  in  1992, when  EPA's Phase  I  volatility control  program is
superseded by Phase  II  volatility   control  limits).   The  major
function  of  having two  RVP values as input,  "period  1"  ("base" in
MOBILE4)  and "period 2"  ("in-use"  in  MOBILE4),   is  to  allow  the
user  to  define  a  step  change  in  fuel volatility  at  a specific
calendar year.

     2.2.12.2  Options

     The value used for "period 1" RVP can be  anywhere between 7.0
psi and 15.2 psi  inclusive.  However,  for  accurate  and meaningful
results, the guidance provided below should be followed.

     2.2.12.3  Use in MOBILE4.1

     The  "period  1"  RVP is used  in MOBILE4.1, for  calendar years
of  evaluation prior to the  user-specified  "period 2"  start year,
to  account for the effects of fuel volatility  on  emissions.   Thus,
the use of the appropriate value of RVP allows the construction of
more  accurate  emission  factors  and  a  more  accurate  emission
inventory.   If the  calendar year  of  evaluation  is  the same or
later   than   the   specified   "period  2"   start  year,   then  the
"period 1" RVP input  is  ignored  (in the  sense  that  it  will  not
have any  impact on the emission factors for the evaluation year).

     2.2.12.4  Required Information

     A  value of  RVP  (in  psi) representing the prevailing average
fuel volatility for  the geographic area of interest, either in the
absence  of   volatility  control   reguirements   or   before  more
stringent control  reguirements takes effect.

     2.2.12.5  Changes Since MOBILE4

     The  name of  this variable  has been changed from "base RVP" to
"period 1 RVP."  There have been no  revisions  since  the release of
MOBILE4 to the definition or  input reguirements for this variable.

     2.2.12.6  Guidance

     As with the  temperature inputs discussed above,  the"intended
use of the  MOBILE4. l  run determines  the  season  for  which  the
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average  RVP  should  be  ascertained.   For  ozone-related  (summer
season) modeling,  use summer (July)  RVP.   For CO  (winter  season)
modeling,  use  winter  (January)  RVP.  Note that MOBILE4.1  does not
model effects  of RVP  on  exhaust emissions at temperatures  of  less
than  45°F  (7°C),  and that no  effects  of fuel volatility greater
than  an  RVP of  11.7 psi  are  modeled.   If  modeling of  emission
factors is being performed  on a month-by-month basis, the value of
RVP  appropriate  to  each  of the  specific  months  being  modeled
should be  used.   It is  not correct  to average  RVP values  from
different months or seasons  together,  or to use RVP  from  a season
other  than  that used to determine the  temperatures  used  in the
emission factor modeling.

     Further  guidance on   the  determination  of  the  appropriate
values to use  as  input  for fuel RVP is provided in "Procedures for
Emission  Inventory   Preparation,  Volume IV:   Mobile   Sources,"
EPA-450/4-81-026d (revised), July 1991.


2.2.13  "PERIOD 2" RVP and "PERIOD 2" START YEAR

     2.2.13.1  Description

     EPA has issued rules reguiring that  fuel  RVP  during the ozone
season be  limited  to 10.5  psi RVP  in  most parts of  the country
(roughly corresponding to  ASTM Class  C  areas)  during  the summer
ozone-season months   in 1989-91  (Phase  I volatility  control), and
to 9.0 psi  RVP during the  summer ozone-season months in  1992 and
later  (Phase  II  control),  with  generally  proportional  reductions
in summer fuel maximum RVP in other States  (roughly  corresponding
to ASTM  Class  A and  B  areas).    MOBILE4.1 provides the  ability to
model the effects  of  an  RVP control program through  specification
of the "Period  2"  RVP  limit and  the  calendar  year in  which the
requirement  is effective.

     2.2.13.2  Options

     The  user  must  input   values  for  the  "period  2"  RVP  and
"period 2"  start year.   The RVP value can be  between 6.5 and 15.2
psi  inclusive.   The earliest allowed in-use start year is 1989.

     2.2.13.3  Recpaired Information

     The RVP  level  to  be  assumed (psi) for  "period  2"   and the
calendar year  in which the control program is first effective.

     2.2.13.4  Changes Since MOBILE4

     The  names  of  the  variables have  been changed  from  "in-use
RVP"  and "in-use  start  year"  in MOBILE4  to "period  2  RVP"  and
"period  2  start  year."   There have been  no  revisions in the  input
or formatting  of these two variables since the release of MOBILE4.
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     2.2.13.5  Guidance

     To  model  the  effects  of  the  Federal  volatility  control
program  issued  by EPA,  in  which volatility  is  limited  in  the
summer months  (May through  September),  see  the relevant  Federal
Register  notices  (54  FR  11868,  March  22,   1989;   55  FR  23658,
June 11,  1990),  or contact your  EPA Regional Office  to  determine
the  applicable  RVP limits  for  a  specific State  and month.   The
interim  (Phase  I)  controls were  in  effect during  1989  and  1990,
and  the  final  (Phase  II)  controls  take  effect  beginning in  the
summer of 1992.

     EPA will accept the use of the Federal RVP  limits  for  a  given
area  as  the  fuel RVP  for the highway  vehicle emission factors  and
inventory.   However,  greater  accuracy  is  possible  by using  the
results of local  fuel  survey RVP measurements, or by adjusting the
regulated RVP  limit to  reflect  the  degree to  which  typical  fuel
RVP  fall  below  the limits  effective  for areas and months with fuel
survey  data.    For  areas   without   fuel  survey   data,   typical
commercial fuel  subject  to  an RVP limit of 9.0  psi  can be assumed
to  have  8.7  psi RVP.    For  RVP  limits  of 7.8  psi  or   lower,  no
"margin of safety"  should  be assumed,  since the cost of creating a
safety  margin is  greater.   The  margin  can  be estimated  through
interpolation  for  RVP  limits between  7.8  and 9.0  psi.   It  is  not
correct to use  the actual  RVP limit in  the base year and  then to
include a safety margin  in modeling the projection years.

     The  effects   of   local   (State,   regional)  fuel  volatility
control  programs,  which may  be  more stringent  and/or  take effect
sooner  than  Federal  controls,  can  be  modeled  by  appropriate
selection of  values for  "period 2"  RVP  and start year.   To  model
the  effect  of a fuel volatility  control program,  use the proposed
RVP  limit as the value  of  "period 2" RVP,  and the  year  in  which
the  program takes effect as the "period 2" start year.

      If  no  changes in  fuel volatility are  to be assumed, then the
value  of "Period  1"  RVP  should be  used  for   "Period  2"  RVP as
well.   In this case,  with no change  in  RVP between "period 1"  and
"period 2," the  period 2 start year should be set at 2020.


2.2.14  OXYFLG

      2.2.14.1  Description

      There  are two optional  flag  settings  that  appear as the  last
two  variables  of the  LAP record.  The first  of  these is OXYFLG,  a
flag that tells MOBILE4.1  whether or not the user intends to model
the  impact  of oxygenated fuels  on exhaust CO  emissions.   If  this
flag is  missing,  MOBILE4.1  will  interpret  its  value as  "1"  and
will not  expect  to  see additional  input data  on  oxygenated fuels.
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     2.2.14.2  Options

     This flag has two  possible  values,  1 and  2.   If OXYFLG  =  2,
then the  user must  supply  an  additional input  record  containing
data on  the  average  oxygen  content  of  two  types  of  oxygenated
fuels  (gasoline/alcohol  and gasoline/ether  blends),  the  market
penetration of each type  of  oxygenated fuel, and whether  or  not  a
an RVP  allowance  (+1.0 psi)  for  alcohol-based  oxygenated  fuels  is
in  effect  in  the  area  being  modeled.   See  section  2.3.9  for
information on the placement and content of this record.

     If OXYFLG =  1, then  the model assumes that no oxygenated fuel
information will  be  included in  the  remainder of  the  input  data
file, and no effects of  fuel oxygen content  on  emissions will  be
modeled.  If this flag is missing, it will be interpreted as "1."

     2.2.14.3  Repaired Information

     No information is  required;  as noted  above,  if this  flag  is
not present  at the end of the LAP record (following the in-use RVP
control start year),  it will be interpreted as  being  set  to 1.  If
the effects  of an oxygenated fuels program on exhaust CO emissions
are to be included  in the modeling, this flag  must  be  present and
set to 2.

     2.2.14.4  Use in MOBILE4.1

     The  use of  oxygenates   in  gasoline,  whether  in the  form  of
alcohols  or  ethers,    leads  to   reductions  in   carbon  monoxide
emissions.   MOBILE4.1  incorporates  the  effects  of  fuel  oxygen
content,  as  specified  by  the modeler, on CO emissions.   If an RVP
waiver  is in effect for  alcohol-based  oxygenated fuels,  such that
the  volatility limit   for  such  fuels  is  higher  than  that  for
straight  gasoline,   then  this   "RVP  boost"  will  also  result  in
slight  increases  in exhaust  HC,  CO, and NOx emissions  relative  to
the case  where no waiver  is in effect.

     2.2.14.5  Guidance

     If   oxygenated  fuels  are  known to  have significant market
penetration   in  the  area  being  modeled,  then  this  should  be
reflected in  the highway  vehicle emission factors  and   emission
inventories  prepared  by States  (or local or regional  entities)  in
response  to the requirements  of the 1990 CAA amendments.
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2.2.15  DSFLAG

     2.2.15.1  Description

     The  other  optional  flag  at  the  end  of  the  LAP  record  is
DSFLAG,  which  instructs  MOBILE4.1  as  to  whether  the  user  is
supplying alternate  diesel  sales fractions by model  year for LDVs
and LDTs.  As  in  the case  of OXYFLG,  if  this  flag  is  missing  it
will be  interpreted  as  having a value of 1, and the model will not
expect  to find alternate  diesel  sales  fractions  as part  of  the
model input data).

     2.2.15.2  Options

     This flag  has two possible values,  1 and 2.   If  DSFLAG = 2,
then the  user must supply 50 diesel  sales fractions (25 each for
LDVs  and LDTs,   for  model  years  from  the  calendar  year  of
evaluation back to 25  model  years ago) for  each scenario  of  the
run.   The placement  of these fractions,  format  requirements,  and
additional information  appear in section 2.3.10.

     NOTE:   If  the user  wishes to  supply alternate diesel sales
fractions by model  year  for  LDVs and  LDTs,  then  the  entire LAP
record must  appear in the Scenario data section  for  each scenario
of  the run.   In other  words, if DSFLAG =  2  is  chosen,  LOCFLG =  1
MUST  be  chosen.   The  reasons  for this  are discussed  in  section
2.3.10.   If  the  input  file  violates  this  condition by  including
DSFLAG =  2 on the  LAP record, but  contains  only  one LAP  record for
all  scenarios,  an  error message will be produced and the run will
not be executed.

     2.2.15.3  Recpaired Information

     No  information  is  required;  as noted above,  if this flag is
not present  at  the end of the LAP record  (following  the  in-use RVP
control   start  year  and  the  value  of   OXYFLG),   it  will  be
interpreted   as  being   set  to   1.   If   alternate  diesel  sales
fractions by model  year  for LDVs  and  LDTs are  to  be  included in
the  modeling, this  flag must  be  present  and set  to   2,  and the
entire LAP record  must  appear in the Scenario data  section.

     2.2.15.4  Guidance

     Sales   of  diesel   powered  light-duty  vehicles   and   trucks
underwent a  surge in  the  late  1970s  and  early  1980s,  peaking at
5.9 percent  of nationwide LDV sales  in  the 1981  model year,  and at
9.3  percent  of  nationwide LDT sales in the 1982  model year.  Since
then diesel  sales  have  fallen precipitously, to virtually zero for
LDVs  (less  than 0.05 percent of all LDV sales  in model  years 1988
through   1990)  and to  about  0.2  percent  of LDTs  since  the 1988
model  year.
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     MOBILE4.1, like  earlier  versions of the model,  uses  a single
set  of  registration  distributions  by  age  and  annual   mileage
accumulation  rates  to  describe  all  LDVs,  and  another  set  to
describe  all  LDTs.    The  use of  model-year-specific diesel  sales
fractions allows  MOBILE4.1  to internally  split  the LDVs  and LDTs
into  gas   and  diesel   sub-categories,   which  have   distinctly
different emission rates and behaviors.

     To  assist those areas  having access to vehicle registration
data  that distinguishes  between  gas  and  diesel  LDVs  and  LDTs,
provisions have been  made in MOBILE4.1  to allow the  user  to input
alternate  (locality-specific)  diesel  sales  fractions  by  model
year.   These   data  must  be  supplied  for every  calendar   year  of
evaluation:   Since they apply to vehicles of ages 1,  2,  3,  ...,  to
25-and-older,   different  sets of  fractions  are  required  for each
calendar year.

     The input of alternate diesel  sales  fractions  is discussed in
section  2.3.10.   Areas  having   the  necessary  information  for
development of these  sales  fractions by model year  are  encouraged
to  incorporate their  own diesel sales  fractions by model  year for
use  in  the  construction  of  the base year  inventories.    EPA will
accept  the use  of   the  built-in  national  average diesel  sales
fractions in modeling emission factors  for use  in constructing the
mobile  source  portion  of  the  base  and projection  year  emission
inventories.   Additional  guidance  on diesel  sales  fractions  to be
used in projection year modeling will be provided at a later date.


2.2.16  BY MODEL YEAR INCLUSION VECTOR

     2.2.16.1  Description

     If  the user  chooses  to  have  MOBILE4.1  provide  additional
output  tables   showing  the  relative contribution  of vehicles  of
each  model  year  to  the  average  fleet  emission  factor,  for each
vehicle  type,  then  an additional  input  record that tells MOBILE4.1
which  vehicle  types  the  additional  output  is  requested   for  and
what  additional  information  is   requested  must  appear  in  the
One-Time Data  section of  the input.  This option  is  available by
setting  OUTFMT = 5 (see  sections  1.1.14  and 2.1.15).   This  record
is  essentialy  a  string of "yes/no" flags, as described  below.   If
used, it appears as the last One-Time Data section input record.

     2.2.16.2  Options

     If  the "by  model  year" option has  been  selected,  then the
modeler must specify  for  which  vehicle  types the additional  output
information is desired.   (Since running MOBILE4.1 in the  "by model
year"  mode  slows program execution dramatically,  it  is suggested
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that the  modeler  carefully consider  the  need for  the  information
provided  before electing this option,  and only select  only those
vehicle types for  which the information is necessary.)

     The  user  can also  choose  three kinds  of  "by model  year"
output:   One  consisting only of  the model year-specific  emission
factors,  one  which  also  provides  the   model  year-specific  I/M
credits  (assuming  that  an  I/M program has  been  included  in  the
modeling),  and  one which also provides   information on tampering
rates and offsets  on a model year-specific basis.

     2.2.16.3  Recruired Information

     If by model year output is requested, then  the last record in
the  One-Time Data section  consists  of   ten  integer flags,  each
having  a  value  of  "1"  or "2."  The  first  eight  instruct MOBILE4.1
whether by  model year  emission factor output is desired (2) or not
necessary (1) for  each vehicle type,  in this order:   LDGV,  LDGT1,
LDGT2,  HDGV,  LDDV,  LDDT,  HDDV,  and  MC.   The   last  two  flags
instruct  MOBILE4 . 1  whether  the   by  model  year  output  for  I/M
program  effects  and tampering rates  and  offsets are desired; each
of these  is coded  such that 1 = "No" and 2 =  "Yes."

     The  format of this record is:
     An example is shown bel'ow:

           22211111 2 1

 In  this example,  by model  year emission  factors and  I/M credit
 information  are  requested  for  light-duty  gas  vehicles  and both
 classes of  light-duty gas trucks;  no by model year  information is
 requested  for  the other  five vehicle types,  and  no  by model year
 tampering information is requested.

     2.2.16.4  Guidance

     This option  is provided for special modeling purposes.  There
 is  no  need for  this  option  to  be  exercised in  the development of
 mobile  source emission factors  and  inventories.   Due  to the memory
 required  to  exercise  this option,  selecting  it  results   in   a
 dramatic  increase  in  the  time necessary to  execute  MOBILE4 . 1
 runs.   Modelers  with a  need  for  such information,  and  desiring
 further  information  than is provided in this  section,  are advised
 to  contact EPA for assistance.


     This concludes the One-time data section.
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2.3  SCENARIO SECTION

     The Scenario  data  follow the  One-time  data in  the  MOBILE4.1
input  stream,  and are  used to  assign values  to those  variables
that specifically  define each of  the scenarios  to  be  evaluated.
It  consists  of  one  to  six records,  depending  on  the  values
assigned  to the  flags  in the  Control  section and to  the  two
optional flags on the LAP record.

     The user  can calculate emissions for  one or  more  scenarios.
Each scenario  is  associated  with  one  group  of Scenario  section
records.   The  program  terminates  execution  upon  detecting  an
end-of-file condition.

     The first record,  consisting  of those variables  discussed in
sections 2.3.1  through 2.3.5, must  be included  for every scenario
of  every  MOBILE4 run.   The  second possible record,  required only
if  LOCFLG = 1,  consists of local area parameters to be applied for
this scenario  only  (see sections  2.1.13,  2.2.8 through 2.2.13).
The third possible record is  required only if the user has elected
to model the effects on exhaust  CO  emissions of  an  oxygenated fuel
program  (and  the  associated volatility   impact on all  exhaust
emissions if an  RVP  waiver for  oxygenated  fuels is  in  effect) by
setting OXYFLG  = 2  on  the LAP  record.  This  record  would then be
the  oxygenated  fuel  descriptive   record,  discussed  in  section
2.3.9.    The fourth  through  sixth  possible  records  are required
only if the user  has  chosen to input diesel  sales  fraction data
for LDVs  and LDTs by setting DSFLAG = 2 on  the  LAP record.   These
records would  then contain the  alternate  diesel sales  fractions,
as  discussed  in  section  2.3.10.   The  seventh possible  record,
required only if VMFLAG = 3, consists of the VMT  mix  to  be applied
for this  scenario  only (see sections 2.1.6 and 2.2.2).  The eighth
and  last possible record,  required only  if  ALHFLG =   2   or  3,
consists  of either  six  or  ten additional  input  values used to
correct certain  exhaust emission factors (see sections  2.1.10 and
2.3.7).

     Table  2.3-1 summarizes the Scenario  section input record(s),
including the variable names, codes,  and allowable  values for each
field.


2.3.1   REGION

     2.3.1.1  Description

     The  first  specification required in  the first  record  of the
Scenario  data  section is the region for which emission factors are
to  be  calculated.
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     2.3.1.2  Options

     MOBILE4.1 provides two  options  for region:   low-altitude  and
high-altitude.   Low-altitude   emission  factors   are  based   on
conditions representative of approximately 500  feet  above  mean  sea
level  (+500  ft  MSL),  and high-altitude   factors  are  based  on
conditions   representative  of    approximately  +5500   ft   MSL.
MOBILE4.1,  like MOBILE4,  does not  calculate  California  emission
factors.

     2.3.1.3  Use in MOBILE4.1

     The region selected determines whether  the MOBILE4.1  emission
factor calculations will be based on low-altitude or high-altitude
basic  emission  rates,  and  if  applicable  whether  low-altitude  or
high-altitude  I/M credits  will  be  used.   (If high-altitude  I/m
credits are  to  be  used, they must be supplied  as  a separate input
file of alternate credits.    See section 2.2.5.)

     2.3.1.4  Repaired  Information

     A value of either 1  (low-altitude) or  2 (high-altitude) must
be entered for the region.

     2.3.1.5  Changes Since MOBILE4

     There have been no revisions to  this  variable or how  it  is
input to the model since the release of MOBILE4.

     2.3.1.6  Guidance

     For  the majority  of  MOBILE4.1 applications,  low-altitude  is
the  appropriate  choice.    For those   areas  designated  as  high-
altitude  by EPA  for  mobile source regulatory  purposes,  generally
those  counties  that   lie   "substantially"  above   +4000  ft  MSL,
high-altitude  should be  selected.  A  list  of  those  counties  EPA
has  designated  as  high-altitude  appears in  §86.088-30, paragraphs
(a)(5)  (ii)  and (iv), Code  of Federal Regulations.


2.3.2  CALENDAR YEAR

     2.3.2.1  Description

     The  value used  for   calendar  year in  MOBILE4.1  defines  the
year  for  which  emission   factors are to  be  calculated  (as  of
January 1).   It is frequently referred to as  the  calendar year  of
evaluation.
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                               2-50

     2.3.2.2  Options

     MOBILE4.1 has  the ability to  model  emission factors  for  the
years 1960 through 2020 inclusive.

     2.3.2.3  Required Information

     You must enter  a  value for the last 2 digits  of  the calendar
year of evaluation (range 60-99 and 00-20).

     2.3.2.4  Changes Since MOBILE4

     There  have  been  no  revisions to this variable or how  it is
input to the model since the release of MOBILE4.

     2.3.2.5  Guidance

     Different  uses   of  the  emission   factors   calculated   by
MOBILE4.1   require   special  treatment.    The   base  year  (1990)
inventories  are  supposed  to be  based  on  a  typical  day in  the
pollutant  season,  most  commonly  summer  for  ozone  and  winter  for
CO.   Thus  the  base  year  HC   inventories  should  be  based  on
interpolation  of   the  calendar   year  1990   and   1991  MOBILE4. l
emission  factors.   CO  inventories generally  should  be  based on
emission  factors  from a  single calendar  year of  evaluation.   For
example,  if  the  three-month  period  for  which  CO emissions  are
being modeled was  December 1989 and January and February  1990,  the
use  of  1990  for  calendar  year  would  be  appropriate.    If  that
three-month  period  is instead  November  1990  -  January  1991,  then
calendar  year 1991  emission factors  would  be  more  appropriate.
Questions  regarding  the  best calendar year  to use for CO modeling,
if not addressed by the examples  above, should be  addressed to the
EPA Regional Office.

     Similar  instuctions  apply  to  the  development  of  reasonable
further  progress  (RFP)   inventories.   For  modeling  of   specific
episode  days,  the best  results will be  obtained  by interpolating
exactly  to the day  being modeled.  In  attainment  demonstrations,
it  is  acceptable  to account for  fleet turnover through November 15
of the year being modeled.


2.3.3  SPEED

     2.3.3.1  Description

     Emission  factors  vary  considerably with  the  average  speed
assumed.   The value(s)  input  for speed  in MOBILE4.1  will  have a
significant  impact on the resulting emission factors  for exhaust
and  running  loss  emissions.   The speed  correction  factors  have
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                               2-51

been extensively  revised since MOBILE4.   In general, it  is  still
the case that  exhaust  emissions  are at a minimum  at  approximately
the average  speed of  the  Highway Fuel Economy  (HFET)  test cycle,
or about 48 mph.   The  general curve describing all emission  rates
(HC, CO, NOx)  as  functions  of speed displays very high emissions
at very  low speeds, with  emissions decreasing (sharply  at first,
then  more  slowly)  as  average  speed  increases,  until  minimum
emissions  are  reached  at  around  48  mph.   Above  48  mph,  further
increases in speed result in increased emissions.

     2.3.3.2  Options

     You  have  the  option  of using  one  average speed  for  all
vehicles (by setting SPDFLG =1)  or of  using eight average speeds,
one for  each vehicle type  (by setting SPDFLG = 2).  MOBILE4. l will
calculate emission  factors  for average speeds of  2.5 to  65.0  mph,
in  increments  of 0.1  mph.   If a  speed below 2.5  mph  is input,  a
warning  message  will be issued  by MOBILE4.1  and  2.5 mph  will  be
used in the calculations.

     Similarly,  if  a  speed  above 65  mph  is  input,   a  warning
message  will  be   issued  and 65.0  mph  will  be  used  in  the
calculations.   Note  that  the  maximum  speed  of 65  mph is  an
increase from the maximum 55 mph  average speed allowed by MOBILE4.

     2.3.3.3  Use of Average Speed  in MOBILE4

     The data  base  on  which all emission factor  calculations are
based  is  developed  from  vehicle  test  results   at  based on FTP
conditions,  including  the average  speed of 19.6  mph.   MOBILE4
adjusts  the  emission   factors  for  speeds   other than  19.6  mph
(20 mph  for  HDGVs and  HDDVs)  through  the use of  speed correction
factors.   Running loss  HC emissions also vary with average speed,
and  that  variation is reflected  in  the  running  loss   emission
factors  produced  by MOBILE4.1.

     2.3.3.4  Required  Information

     You  must  supply  either  a  single value  which  is  assumed to
apply  to all vehicles  (if  SPDFLG = 1,  3,  or 4),  or eight values
(one  for  each  regulated  vehicle  class,  if  SPDFLG =  2)  in the
following order:   LDGV,  LDGT1, LDGT2, HDGV,  LDDV,  LDDT, HDDV, MC.

     2.3.3.5  Changes  Since MOBILE4

     The  choices  available  (one  average  speed  or  eight  vehicle-
specific   average   speeds)   and  the   associated  data   format
requirements   are  unchanged  from  MOBILE4.   In  MOBILE4.1,  the
maximum  average  speed for  which  emission factors  can be calculated
has been increased to  65 mph.
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                               2-52

     2.3.3.6  Guidance

     The  FTP   driving   cycle  was   originally   intended  to   be
representative of driving conditions  typical  of  a standard commute
in an urban  area.   Thus  the use of 19.6 mph  as  the  average  speed
applicable  to   all  vehicle  types  is  appropriate for  approximate
analysis  of  emissions from traffic  in  urban  areas  as  a  whole.
However,  such  an  approach  is not   suitable  for  SIP  inventory
preparation.   Instead,  vehicle  miles travelled  (VMT)  should  be
consolidated into  at least  three  speed categories,  and  MOBILE4.l
used to estimate emission factors for eachy of them.

     The  average  speed  of the  transient  test  cycle  used  for
heavy-duty engine certification  is  20 mph,  which is representative
of urban  driving overall for these vehicles.  Use  of  19.6 mph as
the  average  speed  for all  vehicles therefore leads  to application
of a small  speed correction factor to the  HDGV and  HDDV emission
factors.

     For  some  applications  of  MOBILE4.1,  you might assume a single
value other than 19.6 mph.   For  example, to  model  emission factors
typical of  a stretch of  limited access highway,  the use of a speed
in  the  55  to 65  mph  range  for  all  vehicle  types  would  be
appropriate.

     When,  as   in  SIP  inventory preparation,  MOBILE4.1  runs  are
required  using speed(s)  representative  of   certain  areas  (e.g.,
subsets  of  urban  areas,  specific highway   links)  or of  certain
times  of  day,  there are  often speed data   available  from local,
regional,   or   state  transportation   planning  agencies.    The
prediction  of  average speeds in the  future   is difficult,  and may
be  a critical  factor in some  areas'  ability to  project compliance
with SIP  commitments and  air  quality standards.  A  discussion of
how  average speeds  can  be  estimated from  available data sources
and  additional  guidance on  the  determination  of  average speeds for
use  in highway vehicle  emission inventory  development is provided
in   "Procedures  for  Emission  Inventory  Preparation,  Volume  IV:
Mobile Sources," EPA-450/4-81-026d (revised), July 1991.


2.3.4  AMBIENT  TEMPERATURE

     2.3.4.1  Description

     Emissions  vary  considerably  with  ambient   temperature.   The
value  of  temperature used  to calculate  the  temperature correction
factors   for exhaust emissions,  hot  soak .evaporative emissions,
refueling  emissions,   and  resting  loss  and  and  running   loss
emissions will  significantly affect the resulting emission  factors.
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                               2-53

     If TEMFLG  = 1,  the temperature  used to  adjust the  exhaust
emission factors  for all  three exhaust  pollutants,  the hot  soak
component of evaporative emissions,  the displacement component  of
refueling  emissions,  and  resting   loss   and  and  running  loss
emission factors will be calculated by MOBILE4.1  on the basis  of
the  input  minimum  and  maximum daily  temperatures.   The  ambient
temperature specified here will not be used.

     If TEMFLG  = 2,  the value of  ambient temperature  specified
here  will   be  used  as  the  basis  of  the temperature  correction
factors for all exhaust  emissions, hot  soak evaporative  emissions,
refueling emissions,  and resting  loss  and running loss  emissions.
The  input  values  for minimum  and  maximum  daily temperatures  will
still be used  in calculating  the  diurnal  component of  evaporative
emissions.    The use  of  TEMFLG =  2  causes   the   input  value  of
ambient  temperature to  be used to  correct  the  exhaust  emission
factors in the  same way as was done  in MOBILES.   If  the specified
ambient temperature is  inconsistent  with the minimum and  maximum
daily temperatures  (e.g.,  20°F  ambient with  60°-84°F minimum  and
maximum),  an  error message   will  result  and  processing  of  the
current scenario will be stopped.

     2.3.4.2  Options

     The ambient temperature  specified can range  from 0°F  <-18°C)
to  110°F  (43°C) .   If  a temperature  less  than  0°F  is input,  a
warning  message will  be  issued,  and  0°F  will  be  used  in  the
calculations (if TEMFLG  =  2).   Similarly,  if a temperature greater
than 110°F is input, a warning  is issued,   and  110°F is used in the
calculations (if TEMFLG =2).

     2.3.4.3  Use of Ambient Temperature in MOBILE4.1

     The basic  emission  rates that  underlie  the  emission factor
calculations are developed from emission  data  from vehicles tested
at  FTP  conditions,  at  a nominal test  temperature of 75°F (24°C).
MOBILE4.1  uses  temperature correction  factors to  correct  exhaust
emission  factors  to temperatures other  than  75°F.   Temperature
corrections  are  also   applied to   the   hot   soak  component  of
evaporative  HC  emissions.   Refueling, resting loss, and  running
loss emissions  are  all  functions  of  temperature.   If TEMFLG  = 2,
the  value  input here for ambient  temperature  is used to determine
these correction factors.

     2.3.4.4  Required Information

     A value of ambient  temperature in degrees Fahrenheit (°F).

     2.3.4.5  Changes Since MOBILE4

     There  have been no revisions to this  variable's use  or input
data format  requirements since the release of MOBILE4.
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     2.3.4.6  Guidance

     EPA generally  recommends that  the  minimum and maximum daily
temperatures be used to determine  the  temperatures  for corrections
to  the  emission factors  if  daily average  emissions  are  to  be
estimated,  rather than hour-by-hour emissions.

     If  this  ambient  temperature  is  used  instead,  the  value
specified  depends  in  large  measure on the  purpose  for  which
MOBILE4.1  is  being  used.   Additional  information  and guidance  on
the determination of  appropriate  ambient temperture values appears
in  "Procedures  for  Emission  Inventory  Preparation,  Volume IV:
Mobile Sources," EPA-450/4-81-026d (revised), July 1991.

     The ambient temperature  logically must  be between the minimum
and maximum temperatures.  This  is particularly important when  HC
emission  factors are  being   modeled,  since  minimum  and  maximum
temperatures  are used  in the evaporative  emission  component  of
those  calculations,  and the  evaporative  and exhaust components  of
the  emission  factor  should  be estimated on  a consistent  basis.
Modeling of  CO emission  factors  is more  likely to  focus  on times
with  cooler  temperatures, when most  violations  of  the  National
Ambient Air Quality Standard  (NAAQS) for CO occur.


2.3.5  OPERATING MODES  (PCCN.  PCHC. PCCC)

     2.3.5.1  Description

     One  important   determinant  of  emissions  performance   is  the
mode  of  operation.    EPA's emission  factors are based  on testing
over the FTP cycle,  which  is  divided into three segments (referred
to   as   "bags"),    each   with   differing   associated   emissions
performance.  The bags  correspond  to operating modes:

           Bag       Operating Mode
            1        Cold  start
            2        Stabilized
            3        Hot start

     Emission  data  from each of  these bags  reflect the fact that
emissions  generally are highest  when a  vehicle  is  in  cold-start
mode:    the   vehicle,  engine,   and  emission  control  equipment
(particularly   the   catalytic  converter)   are  all   at   ambient
temperature  and thus not  performing at  optimum levels.   Emissions
are  generally somewhat  lower  in  hot start mode, when the vehicle
is  not  yet   completely warmed up  but  was  not  sitting  idle for
sufficient time  to  have cooled completely to ambient  temperatures.
Finally,   emissions  generally are  lowest  when  the  vehicle  is
operating  in  stabilized mode,  and  has  been in continuous operation
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long enough  for all  systems to  have attained  relatively  stable,
fully "warmed-up" operating temperatures.

     The  three  variables  PCCN,   PCHC,   PCCC  are  sufficient  to
completely define the percent VMT accumulated in each of the three
operating modes by vehicles  in  each of two basic  emission  control
configurations,  non-catalyst   and  catalyst-equipped.    Thus  the
input of values  for  percent  VMT  accumulated  in  hot start  mode by
non-catalyst vehicles,  or in  stabilized mode  by  non-catalyst or
catalyst-equipped vehicles,  is  not  required  as  input.   MOBILE4.1
calculates these quantities from the three values entered.

     The definitions  of  the three variables  and how together they
define  six  vehicle   type/operating  mode  combinations  are  shown
below:

     Vehicle Type   Operating Mode   Defined in MOBILE4.1 as:
     Non-catalyst
     Catalyst
     Catalyst

     Catalyst
     Non-catalyst
Cold-start
Hot-start
Cold-start

Stabilized
Stabilized
     Non-catalyst   Hot-start
PCCN
PCHC
PCCC

1.0 - PCCC - PCHC
1.0 - PCCC - PCHC
(assumed   equal    to    the
stabilized VMT  fraction for
catalyst-equipped vehicles)
PCCC - PCCN + PCHC
     The user  should not expect the sum of  PCCN  + PCHC  +  PCCC to
be  100  percent.   While it is true  that  (percent  VMT in cold-start
mode)  + (percent  VMT in  hot-start mode)  + (percent  VMT  in  hot
stabilized  mode)  always equals  100  percent,  for  both catalyst-
equipped and non-catalyst  vehicles  separately,  the variables PCCN,
PCHC, and PCCC are not equivalent to these variables.

     The  values  of  PCHC,  PCCC,  and   PCCN   are  used  in  the
calculation  of  the  bag-dependent  correction  factors  (such  as
temperature   and  volatility)  for  LDV,   LOT,   and  MC  emission
factors.    It   is   assumed  that  all  diesel  vehicles  and  all
motorcycles are  always non-catalyst.

     2.3.5.2  Options

     The   three   specified   values  must   all   be  expressed  as
percentages  (not as  fractions).   Each value must  lie between 0.0
and  100.0.   The sum of  PCHC +  PCCC must not  exceed 100 percent.
The  value  of  PCCN logically should  be  less  than  that of PCCC, for
the  reasons discussed above.
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                               2-56

     2.3.5.3  MOBILE4 Standard (FTP) Operating Mode Fractions

     The  values  of  the  three  variables  corresponding  to  the
conditions of the FTP cycle are:

                 PCCN              20.6 %
                 PCHC              27.3 %
                 PCCC              20.6 %

These values  reflect  the  same assumptions and conditions  that  are
reflected in other aspects of the Federal Test Procedure.

     2.3.5.4  Required Information

     Three  percentage  values,  reflecting  the  percentage  of  VMT
(not  the  percentage  of  vehicles)  accumulated  by  non-catalyst
vehicles  in  cold-start mode  (PCCN),  by catalyst-equipped vehicles
in  hot-start mode  (PCHC),   and by  catalyst-equipped vehicles  in
cold-start mode (PCCC).

     2.3.5.5  Changes Since MOBILE4

     There have been  no revisions in the definitions or in the use
or  format requirements  of  these  variables  since  the release  of
MOBILE4.

     2.3.5.6  Guidance

     EPA  historically has  defined cold starts to be any start that
occurs  at least four  hours after the  end  of  the  preceding trip for
non-catalyst  vehicles and at  least one hour  after  the  end of the
preceding  trip for   catalyst-equipped  vehicles.  Hot  starts  are
those starts  that  occur less than  four hours  after  the  end of the
preceding trip  for non-catalyst  vehicles and  less  than  one hour
after   the   end  of   the   preceding  trip  for  catalyst-equipped
vehicles.  The  shorter time interval associated with the cold/hot
start definition  for  catalyst-equipped vehicles reflects the fact
that  catalytic  converters  do  not  operate at  intended  efficiency
until they  are fully warmed up  (to  operating temperatures in the
600°F   (316°C)  range);  thus   catalyst-equipped  vehicles   reflect
"cold-start"  emissions performance  after a much  shorter  off time
than  do non-catalyst  vehicles, which do not  depend on attainment
of   such   high  temperatures   for  stabilization   of   emissions
performance.

      In the  absence of  supporting  data  for  values  other than those
listed   above,   EPA   believes  that  the  values   reflecting  FTP
conditions  are appropriate  in many  cases.    This  is particularly
true  when  the  emission  factors  being  modeled  are  intended  to
represent a  broad geographic area  (Metropolitan Statistical Area,
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entire state)  and/or a wide time period  (days, months).   When the
modeling  is  intended  to  represent  highly  localized  conditions
(specific  highway  links)  or  very  limited  periods  of  time  (as
single hours),  it may  be  possible to develop  more  representative
values  for these variables.   Areas  known  to have  average  trip
lengths  significantly shorter  or  longer  than  7.5  miles  may  also
merit the use of  alternate values.

     Thus  for  SIP-related  modeling,  EPA will accept the use of the
FTP  operating  mode values except  for small  scale  scenarios where
their  use  would  clearly  be inappropriate.   EPA will not  accept
SIP-related  modeling  that   includes  different   operating  mode
fractions  for  the  base  and   projection years  without  adequate
quantitative written  justification.

     There are several ways  of  approximating  the  percentage  of VMT
accumulated in each  mode for each type of vehicle, although highly
accurate  determinations are  not  readily  obtainable.   Guidance on
three  possible methods for  determining  the cold-start/hot-start
VMT  fractions  for  non-catalyst  and  catalyst-equipped  vehicles,
including  references to generally available  data sources, appears
in  Chapter 8  of  the  report  "Techniques  for Estimating MOBILE2
Variables."

     Some  transportation  emissions  modeling approaches  are based
on  the  concepts  of  trip-start  emissions  and running emissions,
rather   than  the method  described  above.   MOBILE4.1  does  not
directly mesh  well  with this  approach,  but  can  be  manipulated to
do  so.   Modelers should contact EPA  to discuss the suitability of
this approach  and for assistance  in using MOBILE4.1  to develop the
appropriate emission factors.


2.3.6  VEHICLE MILES TRAVELLED MIX by vehicle  type

     The VMT mix  was discussed  in  section 2.2.2.   This record must
appear  in the Scenario data section  if different VMT mixes  are to
be  applied to  each scenario (VMFLAG =  2),  and must  appear  in the
One-time data  section if the same VMT mix  is to  be applied to all
scenarios  (VMFLAG =  3).  The information  provided in  section 2.2.2
is  applicable  in either case.    This  record  is not required if the
MOBILE4  VMT mix is to be used  (VMFLAG =1).


2.3.7  LOCAL AREA PARAMETER  RECORD

     The  local   area  parameter   (LAP)   record  was   discussed  in
sections 2.2.8 through  2.2.13,  and  is summarized  in Table 2.2-5.
It  must  appear   in  the Scenario  data  section if  a different LAP
record  is to  be  applied to each  scenario  (LOCFLG  =  1),  and must
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appear  in  the One-time data  section if the same LAP  record  is to
be applied for  all  scenarios  (LOCFLG =2).  If the  user  elects to
supply  diesel  sales fractions  by  model  year  as  input data  by
setting DSFLAG = 2  on  the LAP record, then the LAP  record must be
included for  each  scenario.  The  information  provided in sections
2.2.8 through 2.2.13 is  applicable  in  either  case.   This  record
must  be  supplied,   in  either  the  One-time  data  section or  the
Scenario data section,  for every MOBILE4.1 run.


2.3.8  Additional Correction Factors for
       Light-Duty Gasoline-Fueled Vehicle Types

     2.3.8.1  General Description

     MOBILE4.1 provides the capability  of  applying four additional
correction  factors  to the  exhaust emission  factors for  LDGVs,
LDGTls,  and  LDGT2s.  These factors  are used  to  represent  unique
conditions not  typically  assumed  in MOBILE4.1 runs,  which  is why
they  are segregated from other  correction factors  (such as  speed
and temperature).

     These factors  allow  for exhaust  emission factors only  to be
adjusted to  account for  the  emissions  impact  of  air  conditioning
(A/C) usage,  extra  loading,  and  trailer towing.   There  is also a
humidity  correction factor,  which  applies only  to   exhaust  NOx
emissions and is also applied to motorcycles.

     2.3.8.2  Options

     Depending   on  the  value  assigned  to  the   ALHFLG   flag
controlling   the   application   of  these  additional  correction
factors, six  or ten  input values may be  required.

When ALHFLG = 2, six values are required:

  1)  One A/C usage  fraction  (for all LDGVs and LDGTs)
2-4)  Three extra load usage  fractions  (for LDGVs, LDGTls, LDGT2s)
  5)  One trailer towing  fraction  (for  all LDGVs and LDGTs)
  6)  One humidity  level  (for all LDGVs  and LDGTs plus motorcycles)

When ALHFLG = 3, ten values are required:

   1) One A/C usage  fraction  (for all LDGVs and LDGTs)
 2-4) Three extra load usage  fractions  (for LDGVs, LDGTls, LDGT2s)
 5-7) Three trailer  towing  fractions (for LDGVs, LDGTls,  LDGT2s)
   8) One humidity  level  (for all LDGVs  and LDGTs plus motorcycles)
9-10) Dry bulb  and  wet bulb temperatures (used to  calculate an A/C
      usage fraction for  LDGVs and LDGTs).
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                               2-59

     Each of  these  f.ive types  of  input (A/C, extra  load,  trailer
towing, humidity, and temperature)  are discussed  below.

     2.3.8.3  A/C Usage Fraction

     2.3.8.3.1  Description

     If  you wish to  include the  effect on  the exhaust  emission
factors  of  A/C  usage,  enter a nonzero value  for  this  variable and
appropriate dry and wet bulb temperatures,  as explained below.

     2.3.8.3.2  Options

     This   fractional   value   must   be  between  zero  and  one
(0.0 _< AC < 1.0).

     In  the six  value  option  (ALHFLG  = 2), no  correction factor
for A/C  usage will be  applied, regardless  of the  value  that  is
entered.  Entering 0.0 as the value is recommended in this case.

     In  the ten  value  option (ALHFLG =3), the variable  acts as a
flag,  and the A/C usage fraction  will  be  calculated on  the basis
of  the dry bulb  and  wet bulb  temperatures  (see  section 2.3.8.7).
If  0.0  is  entered,  no correction factor will be  applied,  although
values of dry and wet bulb temperature must still be provided.  To
have  a  correction  factor  for  A/C usage  calculated  and  applied,
enter  a  nonzero  value  (0.0 < AC <_ 1.0)  and  appropriate values for
dry and  wet bulb temperatures.

     2.3.8.4  Extra Load Usage Fractions

     2.3.8.4.1  Description

     These  values  are used  to  model the exhaust emissions  impact
of  vehicles carrying an extra  500 Ib  (227  kg)  load.   If you wish
to  include  this effect, three  fractional  values are  entered (one
each  for LDGVs, LDGTls, and  LDGT2s),  representing  the fraction of
all vehicles of the given type carrying such an extra load.

     2.3.8.4.2  Options

     These values must all lie between  zero  and  one.   If the value
entered  is zero, no  correction for  the effects  of extra  load is
applied.

     2.3.8.5  Trailer Towing Usage Fraction

     2.3.8.5.1  Description

     These  values  are  used   to  model  the  impact  on   exhaust
emissions  of vehicles  towing  trailers.   If  you wish  to   include
this  effect in  your modeling,  one or three  fractions  are   entered
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                               2-60

representing the fraction  of  vehicles  of a given type that  are to
be assumed to be towing trailers.

     2.3.8.5.2  Options

     Any value  for  this fraction  must  lie between  zero and  one.
If  the value  entered  is  zero, no  correction for  the effect  of
trailer towing is applied.

     In the  six value  option  (ALHFLG  = 2),  one  value  is  entered
and is applied to LDGVs, LDGTls, and LDGT2s.

     In  the  ten value option  (ALHFLG  =  3),   three  values  are
entered, and one each is applied to LDGVs,  LDGTls, and LDGT2s.

     2.3.8.6  NOx Humidity Correction

     2.3.8.6.1  Description

     This value  is  used to  correct exhaust  NOx emission  factors
for   absolute   humidity.    The  value   entered   is   the  absolute
(specific) humidity,  expressed as grains  water  per  pound  of  dry
air.

     2.3.8.6.2  Options

     The value  entered for absolute humidity must lie  between 20
and  140.    If  the  value  entered  is   75,  corresponding  to  the
absolute humidity condition of the FTP, then no correction will be
applied.

     2.3.8.7  Dry and Wet Bulb Temperatures

     2.3.8.7.1  Description

     MOBILE4.1   will   calculate   the   fraction  of   A/C-equipped
vehicles actually  using their  air  conditioning on the  basis  of  a
"discomfort  index," which  in  turn is calculated  from the  dry  bulb
and wet bulb temperatures.

     2.3.8.7.2  Options

     The values  of  each of  these temperatures must  be between 0°
and 110°F  (-18°  and 43°C), inclusive.   In addition, the  wet  bulb
temperature   must   be  less   than  or  equal  to   the  dry  bulb
temperature.   If any  of  these three  conditions are not met,  an
error message will be issued by MOBILE4.1.

     These values  (in °F)  will be used  to  calculate  the A/C usage
fraction  on the basis of  the discomfort  index  only  if  the  ten
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                               2-61

value  option is  selected  (ALHFLG =  3)   and  a  nonzero value  is
entered  for the  variable  AC.    If  used,  this  calculated  value
overrides the value read in for AC as part of the input.

     2.3.8.8  Changes Since MOBILE4

     There  have  been   no   revisions   to  any  of  the  variables
discussed  in this  section,  or  to how they  are  supplied  to  the
model as input data, since the release of MOBILE4.

     2.3.8.9  Guidance

     In  most cases, ozone  pollution episodes occur  during summer
months  and very  warm  to hot  temperatures.   It  is  reasonable  to
assume  that vehicle  air  conditioning usage  is  high under  such
conditions.   The  air   conditioning  correction  factors  that  are
calculated  in MOBILE4.1 are of  uncertain accuracy.   The emissions
impact   for  late  model  year  vehicles  of  operating  the  air
conditioner  is  not well quantified,  and the  fraction  of vehicles
equipped  with  air  conditioning  is  substantially  higher  for  the
vehicle  fleet of the late  1980s than it was  for  the fleet of the
late 1970s.  Thus the  use  of  the air conditioning  corrections  to
the  emission factors  is acceptable,  but is not  required,  in the
development  of  SIP inventories.   EPA  will accept  SIP  inventories
that  do   not   attempt   to  explicitly   account  for  vehicle  air
conditioning use.   The  same approach  that is taken  in developing
the  base  year  inventory  must  also   be  used  for  projection
inventories.

     The  humidity  correction  for NOx  emissions  accounts  for the
fact that when   "excess" water  vapor  in  present,  some  of the heat
of   combustion   heats   water  vapor    rather   than  enhancing  NOx
formation.   As  with  the   air   conditioning  correction,  EPA will
accept  SIP inventories  that do  not  attempt  to  account  for  local
humidity.   If the humidity correction is applied  in the base year,
it's  derivation  must   be   detailed  in  the  emission  inventory
supporting   documentation,   and   it   must  also  be  used  in  any
projection  inventories.

     If  you  believe   that  conditions   applying  to  a   specific
application  of  MOBILE4.1  warrant the  use of  one or more of the
correction  factors  described in this  section,  and desire  guidance
beyond  that  provided above, contact  EPA  for additional information
(Test and Evaluation Branch, 313/668-4325 or FTS 374-8325).
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2.3.9  OXYGENATED FUELS DESCRIPTIVE RECORD

     2.3.9.1  Description

     If  the user  elects  to  model  the effects  of  the  use  of
oxygenated  fuels  on exhaust  carbon monoxide (CO) emissions,  then
the value of OXYFLG  on the LAP record must be  2  (section 2.2.14).
If  this  option  is  chosen,  then  a  record  describing the  market
penetration and  usage  of  oxygenated fuels  in the  time and  area
being  modeled must  be provided.   This record  must  immediately
follow the  LAP record.   Thus  if  the user is applying  a  single LAP
record for  all scenarios  (by  setting LOCFLG = 2),  this record will
appear  immediately  after  the LAP  record  and  before  any  other
One-Time data that may also be included.  If the  user is applying
a distinct  LAP record  for  each scenario  (by  setting  LOCFLG  = 1),
then  the  LAP  record  is  the  second   scenario  record  for  each
scenario,  and  this  record   immediately  follows   as  the  third
scenario record for each scenario.

     2.3.9.2  Options

     The user has  the  choice  of  not  accounting for  the  effects of
oxygenated  fuel  use  (by setting  OXYFLG  = 1  or leaving  the  space
for OXYFLG  blank), or  of accounting  for the effects  of  such fuels
on exhaust CO emission rates (by setting OXYFLG = 2).

     2.3.9.3  Use  in MOBILE4.1

     If  the user  chooses  to model the effects  on exhaust  CO
emissions of the use of oxygenated fuels, the information detailed
below is supplied  and MOBILE4.1 uses  it  to  estimate  the reductions
in  exhaust  CO emissions  that result for gasoline-fueled  vehicle
types (LDGV, LDGT1,  LDGT2,  HDGV,  and MC) .  The effects  on  exhaust
HC  and  NOx emission factors  and on  evaporative  HC  emissions, are
estimated only with respect  to  the  impact of  volatility  (if the
oxygenated  fuels   have  been granted  a  waiver  allowing  higher RVP
than base gasoline in the modeled area).

     2.3.9.4  Required  Information

     If  the user  has  set  OXYFLG =  2,  then the  record  containing
this  information  must immediately  follow  the LAP  record  in the
input  data file.    If  the LAP  record  is   in  the  One-Time  data
section, then  this  record  immediately follows  it  and precedes any
other One-Time data  records that  are being supplied.   If  the LAP
records  are  in   the   Scenario  data  section,  then  this  record
immediately  follows  each  LAP record as the  third   Scenario  data
record for  each scenario.
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                               2-63

     The record consists  of the following five variables:

     o     Ether blend market share  (as  a fraction)
     o     Alcohol blend  market share (as a fraction)
     o     Average oxygen content of ether blend fuels
             (percent weight, expressed  as a fraction)
     o     Average oxygen content of alcohol blend fuels
             (percent weight, expressed  as a fraction)
     o     RVP waiver switch
             [integer value indicating whether alcohol-based
              oxygenated  fuels must  meet the same RVP  limit
              as straight gasoline (value =1), or have been
              granted a 1.0 psi waiver (value = 2)]

     The format of this record is:

           4(F4.3,1X),1X,I1.

     To  illustrate,  the  following  oxygenated  fuel  input  data
record  states  that  3.5  percent  of  the  fuel  sold  in the  area  is
ether  blends  having  an   average oxygen  content  of  2.7  percent
weight, that 12.9  percent  of the fuel sold  in  the area  is alcohol
blends having an  average  oxygen content of 3.1 percent  by weight,
and that an RVP waiver is in effect allowing the volatility of the
alcohol-based oxygenated  fuels  to  be  up to  1.0  psi RVP  greater
that the limit applicable to straight gasoline:

           Column:     1234567890123456789012
     Input record:     .035 .129 .027 .031  2


     2.3.9.5  Guidance

     Areas  that  are known  to have  significant  market penetration
of ether blends and/or alcohol blends should attempt to accurately
characterize  the  relative market   shares  and  oxygen content  of
these  fuel  blends,  and  account for it  in  their  emission  factor
modeling.   Areas  having  insignificant  market penetration  of  both
types of oxygenated fuels may safely disregard  oxygenated fuels in
their modeling.

     EPA  should  be  contacted  for  assistance  in  modeling  the
effects  of  oxygenated fuels  if any of  the following situations
apply:    (i)   the  fuels   available  in  an  area  include  blends
containing both ether(s)  and  alcohol(s) in the  same  fuel,  or  (ii)
an  RVP waiver greater  than  1.0  psi is  applicable  to oxygenated
fuels  in an area,  or  (iii)  no  RVP waiver  is  in  effect  but  the
volatility  of  base  gasoline  is   currently below  the  regulated
limit, or (iv) if two or more types  of  alcohol  blends are marketed
under  different  RVP waiver treatment.  Additional  guidance may be
obtained through  contacting the appropriate  EPA Regional  Office or
the Office of Mobile Sources.
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2.3.10  DIESEL SALES FRACTIONS

     2.3.10.1  Description

     In section 2.2.15, the  use  of diesel sales fractions by model
year for LDVs and LDTs in MOBILE4. l is  discussed.   These fractions
represent the  share of all  LDV  (LDT) sales in a  given model year
which are diesel-powered,  rather  than gasoline-fueled, vehicles.

     2.3.10.2  Options

     The user can  choose  to  supply sets of diesel  sales fractions
by  model  year  for both LDVs  and LDTs that are  locality-specific
(and different from the national  sales  fractions that are included
in  MOBILE4.1),  or  to  use   the  national  sales  fractions.   The
options are  exercised through the value assigned to  DSFLAG,  the
final  variable  on  the LAP  record.   As  noted  previously,  if  the
user is supplying  diesel  sales fraction data,  it  must  be included
in  the  Scenario   data section  and  the  LAP  record(s)  must  also
appear in the Scenario data section.

     2.3.10.3  Use in MOBILE4.1

     MOBILE4.1, like  earlier  versions of  the model,  uses a single
set  of  registration  distributions  by  age  and  annual  mileage
accumulation  rates  to describe  all  LDVs,  and  another  set  to
describe  all LDTs.   This  is  due in  part to  the  fact  that  it is
nearly  impossible  to develop  such information for gas and diesel
vehicles separately,  and  in  part since there is little evidence to
suggest that typical  use patterns,  mileage  accumulation rates,  and
so  forth  are different  for  gas  and  diesel  vehicles.   The  use of
model-year-specific  diesel  sales  fractions  allows  MOBILE4.1  to
internally  split  the  LDVs   and  LDTs  into  gas  and  diesel  sub-
categories,  which  have  distinctly  different  emission  rates  and
behaviors.

     MOBILE4  contained   forecasts of   increasing  diesel  sales.
MOBILE4.1  essentially assumes that diesel  sales  after  1990 will
show no increase from  current very  low levels.

     2.3.10.4  Required Information

     If the  user   is  supplying alternate  diesel  sales fractions as
input  to  the model,  then  the information immediately  follows  the
LAP  record  and the  oxygenated   fuels  descriptive record  (if  the
oxygenated fuels record is present).

     For each  scenario,  the  user must supply the  fractions  of  LDV
and  of LDT  sales that  were diesel  for  each model  year from the
calendar year of evaluation back  to 24+ model years ago.  For
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example, if the  calendar year  of evaluation  is 1990,  then diesel
sales  fractions  for  model year  1990,  1989,  1988,  ...,  1967,  and
1966-and-older LDVs  and LDTs  must be  provided.  If  two  different
scenarios  are  being  run, both for  the  same calendar  year but with
other  differences,  then  the  same  set of  diesel  fractions  would
have to  be supplied  again as part  of  the  second scenario.   If a
scenario with  calendar  year  1995  was  also  being run,  then  the
diesel sales fractions would represent model  year 1995, 1994, ...,
1972,  and  1971-and-older vehicles.  The  same  values would  be used
for the  model  years  in common to the two sets  of  sales fractions,
but the  five oldest  model year values  would "drop off  the end"  of
the  sequence and be replaced  by  sales  fractions for  the  five most
recent model years.

     The  50  diesel  sales  fractions,  25  each  for  LDVs  and  LDTs,
will  constitute  the  next  three  records.    The  format  of  these
records  is:

           20F4.3
           20F4.3
           10F4.3

     The values  are entered in pairs:   The first two  values on the
first  record  are the  diesel  sales  fractions  for LDVs  and LDTs of
age  1  (model year = calendar  year of  evaluation), the second two
values  are the  sales  fractions  for  LDVs and LDTs  of age 2  (model
year = one year  before calendar year  of evaluation),  and  so on,
with  the  last  two  values  on  the third  record  being  the  sales
fractions  for  age 25+  LDVs  and LDTs (model year  =  24+ years before
calendar year  of evaluation).

     Note  that there are no leading  zeros or  spaces in these input
records.   The  fractions should be  listed to three  decimal places,
one  after  another, with the  values  paired to  represent  cars then
light  trucks  of  each  age.     The  MOBILE4.1   diesel   fractions,
formatted  according  to the requirements  above,  appear below  (these
fractions  are  for calendar year 1990,  and  represent  model  years
1990 through 1976-and-older).

.000.002.000.002.000.002.003.003.003.007.009.011.017.023.021.047.047.093.059.056
.044.035.021.018.009.008.005.000.003.000.002.000.003.000.002.000.002.000.001.000
.000.000.000.000.000.000.000.000.000.000
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                               2-66

     2.3.10.5  Guidance

     This option  has  been provided  in  MOBILE4.1 for two  reasons.
First,  some  users  performing  highway  vehicle  emission  factor
modeling may have  access  to vehicle  registration  data,  or  data
from  other  sources,  enabling them to characterize diesel  sales of
LDVs  and LDTs in the  area being modeled.   Particularly  if  these
sales  fractions  differ   significantly   from  those  included  in
MOBILE4.1,   it  will  enhance  the  accuracy of  the emission factors
and  inventory  to  use  those  sales  fractions  as   model  input.
Second, as  can be seen by the sharp rise and  equally sharp fall of
diesel sales in  the  late 1970s and  early  1980s, it is  extremely
difficult  to  forecast  diesel  sales fractions   for  future  model
years.  This provision will  allow modelers  to  account  for  future
increases in diesel sales, if such increases occur.


2.3.11  TRIP LENGTH DISTRIBUTION

     2.3.11.1  Description

     EPA has  determined  through  its running  loss   emission  test
programs that the  level  of  running  loss   emissions  depends  on
several variables:   the average speed  of the travel,  the ambient
temperature, the  volatility  (RVP)  of the  fuel,  and  the  length of
the  trip.    "Trip length"  as used here  refers to the  duration of
the  trip  (how long the vehicle has  been  travelling),  not  on the
distance  travelled  in the  trip  (how   far  the  vehicle  has  been
driven).    Test data  show that  for   any given  set   of  conditions
(average speed,  ambient temperature,  and fuel volatility), running
loss  emissions  are  zero  to  negligible  at   first,  but  increase
significantly  as  the  duration of the trip is extended and the fuel
tank, fuel  lines, and engine become heated.

      In  MOBILE4, the   test  data  available  for the modeling  of
running loss emissions  were  only adeguate to allow these  emissions
to  be modeled as  direct  functions  of  the user-input  temperature
and  volatility;  average speed  and  trip length  were accounted for
internally  to the  model,  using values  representative  of typical
urban  area  traffic  patterns.   MOBILE4.1  contains  significantly
revised estimates of running  loss emissions.

     The additional data obtained  since  the development of MOBILE4
allows running loss emissions  to  be modeled  as a direct function
of  the  input temperature,  fuel  volatility,  and   average  speed.
While  an  internal weighting  of  trip length (duration)  is included
in  the model  and is  used  to estimate  the  running  loss  emission
factors, the  user  now has  the option  of  supplying an  alternate
trip  length  distribution   for  use  in  estimating  running  loss
emissions.   If this option of specifying trip length distributions
 07/91

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                               2-67

is not  selected,  then MOBILE4.l  will calculate  the running  loss
emission factors  on the basis  of an internal  assumed  trip length
distribution.

     2.3.11.2,  Options

     The user  can  let MOBILE4.1  estimate  running loss  emission
factors  using  the  internal  trip length distributions  (by setting
SPDFLG   to   1   or  2),  or  can  supply  a   set   of  trip  length
distributions (by setting SPDFLG to 3 or 4).

     2.3.11.3  Use in MOBILE4.1

     For each combination  of vehicle type and trip length category
(see below),  a  value  representing running  loss  emissions  at  the
standard test  speed,  temperature,  and  volatility  is  contained in
the  coded  data.   This  information,  if  supplied,  is  used  in
weighting  these  factors  together  to  derive  the fleet  average
emission  factor,  which  then  is  corrected  for  average  speed,
temperature, and  fuel volatility.

     2.3.11.4  Recruired Information

     If  a  modeler has the necessary information,  a separate input
data record  of  trip length  distribution  can be  supplied  as input
and  used  in the  calculation   of running  loss  emission  factors.
This  record must  list the  percentage  of all  travel  (VMT)  being
accumulated  over  the  time period that  the  emission factors apply
for, in  trips of  the following  lengths (durations):

     Under 10 minutes
     11  to 20 minutes
     21  to 30 minutes
     31  to 40 minutes
     41  to 50 minutes
     51  minutes and longer

     The format of this record  is:

                  6(1X,F4.1)

     The record may appear in the One-Time data section or in each
Scenario data  section, depending  on value of  SPDFLG  specified by
the user.

     2.3.11.5   Guidance

     Solid  data on trip  length distributions  is  not  likely to be
available  in most  cases.   Thus  for  base year  emission  inventory
development  by  States and  others,  EPA will  accept the use of the
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                               2-68

internal trip  length distributions for  the  estimation of  running
loss  HC emission  factors.   The use  of trip  length  distributions
other  than  that  included  in  MOBILE4.1  in  the  development  of
required   base  year   emission   estimates   must  be   adequately
documented  for  acceptance  by  EPA.    Where   the  transportation
modeling  process  can  produce  reliable  inputs   for  trip  length
distribution,  it  will  allow  more   accurate  estimates   of  the
benefits attributable  to SIP  measures which  shorten  average trip
lengths without eliminating entire trips.
     This completes the Scenario data section.
 07/91

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                               2-69

2.4  SUMMARY OF MOBILE4.1 INPUT SEQUENCE

     Table  2.4-1  summarizes   the  input  sequence  required  for  a
MOBILE4.1  run,   in  the  order  required  by  the  program.   Records
listed  in  parentheses  are  optional,  and  are  only required  if
certain flags  have been  assigned  specific  values  in the  Control
section.


2.5  OBTAINING REFERENCED DOCUMENTS

     Two  of the  reports specifically  mentioned  in the  guidance
subsections  of  this  document,  "Techniques  for  Estimating  MOBILE2
Variables"   and   "Additional   Techniques   for  Estimating  MOBILE2
Variables,"  can  be  obtained  through   the  National   Technical
Information Service (NTIS).   These reports were  prepared by Energy
and Environmental  Analyses,  Inc.,  for EPA under contract (Contract
No. 68-03-2888).  The NTIS number is:

       Report Title                                 NTIS Number

     "Techniques for Estimating MOBILE2
      Variables" and  "Additional Techniques
      for Estimating MOBILE2 Variables"
     (both  reports come as one order)             PB 83 183277

For price information and to order, contact

     National Technical Information Service
     U. S.  Department of Commerce
     5285 Port Royal Road
     Springfield, VA  22161
     Attention:  Sales

     Phone:  (703) 487-4650

     The  User's  Guides to the earlier versions  of the  emission
factor model (MOBILE2,  MOBILES,  and MOBILE4)  are also available
through NTIS at the  above  address,  for  those who might wish to
obtain them:

                      Title:  User's Guide to MOBILE2
                  NTIS Ref:  PB 81 205619
            Estimated  Costs:       Paper - $53.00
             (as  of 7/1/91)   Microfiche - $10.00

                      Title:  User's Guide to MOBILE3
                  NTIS Ref:  PB 84 213974
            Estimated  Costs:       Paper - $53.00
             (as  of 1/1/89)   Microfiche - $10.00
07/91

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                               2-70

                     Title:  User's Guide to MOBILE4
                  NTIS Ref:  PB 89 164271
           Estimated Costs:       Paper - $23.00
            (as of 1/1/89)   Microfiche - $ 8.00

     The   report   referenced   in   section  1.0,   "Guidance   on
Estimating Motor  Vehicle  Emission Reductions  From  the  Use  of
Alternative Fuels  and Fuel  Blends,"  is  also  available  through
NTIS:

                     Title:  Guidance    on   Estimating    Motor
                             Vehicle  Emission   Reductions   From
                             the  Use  of  Alternative  Fuels  and
                             Fuel Blends
                  NTIS Ref:  PB 88 169594/AS
            Estimated Cost:       Paper - $19.95
            (as of 7/1/91)

     The  report  "Procedures  for Emission  Inventory Preparation,
Volume   IV:    Mobile  Sources,"    (revised),   EPA-450-4-81-026d
(revised), July 1991, should be available  to  State  and local  air
quality  planning officials  by  contacting their respective  EPA
Regional Offices.
07/91

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                               2-71

                            Table  2.1-1

       FLAGS  CONTROLLING INPUT  TO  AND  EXECUTION  OF MOBILE4.1
Record  Variable
Number    Name
    Content and Codes
                                         Format
Refer to
Section
         PROMPT
         IOUNEW
Flag for prompting of
 remaining Control
 section data
                                                   2.1.1
1 = No prompting, vertical format
2 = Prompting, vertical format
3 = No prompting, horizontal format
4 = Prompting, horizontal format

Values for output units:                 2.1.2

(1) Formatted reports unit
(2) Diagnostic messages unit
(3) Prompting messages unit

(Allowable values for each unit are 1, 2, 3,
 6, 7, or 8.  The default value for all three
 output units is 6.)
         PROJID
80 characters for title
                                          20A4
 2.1.3
         TAMFLG    Flag for optional input
                    of tampering rates

                   1 = Use MOBILE4 rates
                   2 = Input alternate rates1
                                 II
                                                   2.1.4
                                                    II
                                         2.1.5
SPDFLG    Selects speed for each
           vehicle type; also flag       	
           indicating whether alternate
           trip length distribution
           data are supplied as input

          1 = One speed for all vehicle types2
          2 = Eight speeds, one for each vehicle type2
          3 = One speed for all vehicle types, plus one
               alternate set of trip length distribution
               data per scenario^
          4 = One speed for all vehicle types, plus one
               set of trip length distribution data for
               all scenarios4  .
 07/91

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                               2-72

                      Table  2.1-1  (continued)

       FLAGS  CONTROLLING  INPUT  TO  AND EXECUTION OF MOBILE4.1
Record  Variable
Number    Name
Content and Codes
Format
Refer to
Section
         VMFLAG    Selects optional use of
                    user-supplied VMT mix
                    among vehicle types
                            II
          2.1.6
                   1 = Use MOBILE4 VMT mix
                   2 = Input one VMT mix for each scenario2
                   3 = Input one VMT mix for all scenarios1
         MYMRFG    Flag for optional input of
                    annual mileage accumulation
                    rates and/or registration
                    distributions by age
                            II
          2.1.7
                   1 = Use MOBILE4 values
                   2 = Input annual mileage accumulation rates1
                   3 = Input registration distributions by age1
                   4 = Input both annual mileage accumulation
                        rates and registration distributions1
         NEWFLG    Flag for optional input of
                    modified basic exhaust
                    emission rates (BERs)
                             II
                   1 = Use MOBILE4 BERs
                   2 = Input one or more alternate BERs1
          2.1.8
          IMFLAG    Flag to include impact of
                    operating I/M program in
                    emission factor calculations

                   1 = No I/M program modeled
                   2 = I/M program modeled1
                             II
          2.1.9
07/91

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                               2-73

                      Table  2.1-1  (continued)

      FLAGS  CONTROLLING  INPUT TO  AND EXECUTION OF MOBILE4.1
Record  Variable
Number    Name
Content and Codes
Format
Refer to
Section
         ALHFLG    Flag to correct exhaust
                    emission factors (gasoline
                    vehicles only) for:
                    (a) air conditioning usage
                    (b) extra vehicle load
                    (c) trailer towing
                    (d) humidity (NOx only)

                    1 = No corrections
                    2 = Input six values2
                    3 = Input ten values2
                               II
          2.1.10
  10     ATPFLG    Flag to include impact of
                    of anti-tampering program
                    (ATP) on emission rates

                    1 = No ATP modeled
                    2 = ATP modeled1
                              II
          2.1.11
  11     RLFLAG    Flag for control of whether
                    and how refueling emission
                    factors are calculated
                              II
          2.1.12
                    1 = Uncontrolled rates
                    2 = Stage II VRS assumed1
                    3 = Onboard VRS assumed1
                    4 = Stage II and onboard VRS assumed1
                    5 = No refueling emission factors calculated
   12     LOCFLG    Flag for control of user
                     input of local area
                     parameter  (LAP) record
                               II
          2.1.13
                     1 = One LAP record input for each scenario2
                     2 = One LAP record input for all scenarios1
 07/91

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                               2-74

                     Table  2.1-1  (continued)

       FLAGS  CONTROLLING  INPUT TO  AND EXECUTION OF MOBILE4.1

Record  Variable                                           Refer to
Number    Name        Content and Codes           Format   Section
  13     TEMFLG    Flag for control of values of     II     2.1.14
                    temperature to be used for
                    correcting emission factors
                    for effects of temperature    	
                   1 = MOBILE4 calculates temperatures to be used
                        in correction of emission factors from
                        input values of minimum and maximum daily
                        temperature; value read as input for
                        ambient temperature is overridden by
                        calculated values.

                   2 = Use input value of ambient temperature to
                         correct emission factors for temperature
 1    Record(s) must appear in One-time data section.
 2    Record(s) must appear in Scenario data section.
 3    Speed  value(s)  appear in  usual  location(s)  on first Scenario
     data  record;  alternate  trip length  distributions  appear  as
     additional Scenario section data records.
 4    Speed  value(s)  appear in usual location(s)  on first Scenario
     data  record;   alternate  trip  length distribution  appears  as
     additional One-Time data section record.
 07/91

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                               2-75

                           Table  2.1-2

              FLAGS  CONTROLLING OUTPUT OF MOBILE4.1
Record  Variable
Number    Name
Content and Codes
Format
Refer to
Section
  14     OUTFMT    Selects the structure of         II      2.1.15
                     formatted output report

                    1 = 222-column numerical
                    2 = 140-column numerical
                    3 = 112-column descriptive
                    4 =  80-column descriptive
                    5 = 112-column descriptive plus
                            "by model year" tables
  15     PRTFLG    Selects pollutants for which
                    emission factors are to be
                    calculated and included in
                    output

                    1 = HC only
                    2 = CO only
                    3 = NOx only
                    4 = All three pollutants
                            II
          2.1.16
  16      IDLFLG    Controls calculation and
                    output of idle emission
                    factors

                    1 = No idle EFs
                    2 = Include idle EFs
                            II
          2.1.17
   17     NMHFLG    Selects composition of "HC"
                    emission factors
                            II
                    1 = Total hydrocarbons  (THC)
                    2 = Non-methane hydrocarbons  (NMHC)
                    3 = Volatile organic compounds  (VOC)
                    4 = Total organic gasses  (TOG)
                    5 = Non-methane organic gasses  (NMOG)
          2.1.18
07/91

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                               2-76

                     Table 2.1-2  (continued)

              FLAGS CONTROLLING OUTPUT OF MOBILE4.1

Record  Variable                                           Refer to
Number    Name          Content and Codes  	   Format   Section
  18     HCFLAG    Selects how HC emission           II     2.1.19
                     factors are output           	
                    1 = No component EFs printed
                         (sum of HC emissions only)
                    2 = Component and total EFs printed
                    3 = Component and total EFs printed,
                         with detailed evaporative emissions
                         breakdown in grams
 07/91

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                               2-77

                           Table 2.2-1

    SUMMARY OF ALTERNATE BER RECORDS (required if NEWFLG = 2)
Record
Field Content, Description, and Codes
Allowable
Format Values

1
2
thru
N+l
1 Number of BER records to follow
1 Code for region new
BER applies to:
1 = low-altitude
2 = high-altitude
2 Code for vehicle type new
BER applies to:
1 = LDGV 5 = LDDV
2 = LDGT1 6 = LDDT
3 = LDGT2 7 = HDDV
4 = HDGV 8 = MC
3 Code for pollutant new
BER applies to:
1 = HC 2 = CO 3 = NOx
4 First model year new BER
applies to (last 2 digits)
5 Last model year new BER
applies to (last 2 digits)
6 New Zero-mile level
7 New Deterioration rate (or DR1*)
8 New DR2*
13, / 1 to 100
11, IX 1 or 2
11, IX 1 to 8
11, IX 1 to 3
12, IX 60-99,
00-20
12, IX 60-99,
00-20
F6.2,1X >. 0.0
F6.2,1X ^ 0.0
F6.2,/ >. 0.0
*  DR2  for model  year  1981  and later LDGV  HC and CO  BERs  only.
Field 8  blank for LDGV  NOx BERs  and  for  all  pollutant  BERs  for
other vehicle types.
07/91

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                               2-78

                           Table 2.2-2

         SUMMARY OF I/M PROGRAM DESCRIPTIVE INPUT RECORD
         	(required if  IMFLAG = 2)	

                                                Allowable  Refer to
Field  Content,  Description,  Codes     Format      Values    Section
  l    Program start year             12,IX       60-99,    2A.1.2
                                                  00-20

       (Last 2 digits of first calendar year of program operation)


  2    Stringency level (percent)     12,IX     10 to 50    2A.1.3


  3    First model year               12,IX       41-99,    2A.1.4
                                                  00-20

       (Last 2 digits of oldest model year
        of vehicles included in program)


  4    Last model year                12,IX       41-99,    2A.1.5
                                                  00-20
       (Last 2 digits of latest model year
        of vehicles included in program)
  5    Waiver rate for pre-1981       F2.0,1X     0 to 50   2A.1.6
        model year vehicles (percent)


  6    Waiver rate for 1981 and       F2.0,1X     0 to 50   2A.1.6
        later model year vehicles (percent)


  7    Compliance rate (percent)      F3.0,1X    0 to 100   2A.1.7


  8    Program type                   II,IX       1 to 3

        1 = Centralized                                    2A.1.12
        2 = Decentralized/Computerized                     2A.1.13
        3 = Decentralized/Manual                           2A.1.14
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                               2-79

                      Table  2.2-2  (continued)

          SUMMARY OF  I/M PROGRAM DESCRIPTIVE  INPUT  RECORD
          	(recruired if IMFLAG  = 2)	
Field  Content, Description, Codes
Format
Allowable  Refer to
  Values    Section
       Inspection frequency

        1 = annual
        2 = biennial
II, IX
  1 or 2
       Enter 1 (not subject to inspection) or
        2 (subject to inspection) for each vehicle
        type, in this order:  LDGV, LDGT1, LDGT2, HDGV
 2A.1.8
10


Vehicle types
inspections

subject to


411, IX 1 or 2
(in each
column)
2A.1.9


 11    Test type

        1 = Idle test
        2 = 2500/Idle test
        3 = Loaded Idle test
II,IX
 1, 2, 3
2A.1.10
 12    Flags to indicate whether
        alternate I/M credits are
        to be  input by user
211
  1 or 2
       Enter  1  (use MOBILE4.1  I/M credits) or
        2  (read in alternate I/M credits on
        logical I/O device unit 4, for Tech  I-II
        and Tech IV+ vehicles  respectively
2A.l.ll
2A.1.15
 07/91

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                               2-80

                           Table 2.2-3

             SUMMARY OF ATP DESCRIPTIVE  INPUT RECORD
             	(required  if  ATPFLG = 2)	
Field  Content, Description,  Codes    Format
         Allowable   Refer  to
            Values     Section

1



2



3



4


Program start year 12, IX

(Last 2 digits of first
calendar year of ATP operation)
First model year 12, IX

(Last 2 digits of oldest model
year of vehicles included in ATP)
Last model year 12, IX

(Last 2 digits of latest model
year of vehicles included in ATP)
Vehicle types subject to 4 11, IX
inspections

60-99,
00-20


41-99,
00-20


41-99 or
00-20


1 or 2
(in each
column)
2A . 1 . 2



2A . 1 . 4



2A.1.5



2A.1.9


       Enter 1 (not subject to inspection) or
        2 (subject to inspection) for each vehicle
        type, in this order:  LDGV, LDGT1, LDGT2, HDGV
       Program type

        1 = Centralized
        2 = Decentralized
  II
l or 2
                     2A.1.12
                     2A.1.13
       Inspection frequency

        1 = annual
        2 = biennial
II, IX
1 or 2
2A.1.8
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                               2-81

                      Table 2.2-3  (continued)

              SUMMARY OF ATP DESCRIPTIVE INPUT RECORD
              	(required if ATPFLG = 2)	
Field  Content, Description, Codes
Format
Allowable
  Values
Refer to
 Section
       Compliance rate (percent)
F4.0,1X   0 to 100   2A.1.7
       Inspections performed
811
  1 or 2
 (in each
  column)
       Enter 1 (inspection is not performed) or
        2 (inspection is performed) for each
        type of inspection, in this order:

         Air pump system
         Catalyst
         Fuel inlet restrictor
         Tailpipe lead deposit test
         EGR system
         Evaporative control system
         PCV system
         Gas cap
                      2A.2.3
                      2A.2.4
                      2A.2
                      2A.2
                      2A.2
                      2A.2
                      2A.2
                 5
                 6
                 7
                 8
                 9
           2A.2.10
07/91

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                               2-82

                            Table 2.2-4

   SUMMARY OF STAGE II  AND ONBOARD VRS DESCRIPTIVE INPUT RECORDS
   	(required if  RLFLAG = 2,  3,  or 4)	

Stage II VRS  Input Record  (required if RLFLAG  = 2 or 4)
                                                          Allowable
Field  	Content, Description, Codes	     Format    Values
       Stage II start year                        12,IX     89-99,
                                                             00-20
       (Last 2 digits of calendar year in which
        Stage II requirement is first effective)
       Phase-in period                              II      1 to 5
       (Number of years allowed for all stations subject
        to Stage II requirement to complete installation)
       Percent efficiency of Stage II VRS         IX,13    0 to 100
        at controlling refueling emissions
        from LDGVs and LDGTs
       Percent efficiency of Stage II VRS         IX,13    0 to 100
        at controlling refueling emissions
        from HDGVs
Onboard VRS Input Record (required if RLFLAG = 3 or 4)
                                                          Allowable
Field  	Content,  Variable Name,  Codes	   Format    Values


       Onboard start  year                         12,IX     89-99,
                                                            00-20
       (Last 2 digits of first model year
        vehicles are  subject to onboard VRS requirement)


       Vehicle types  covered                      411        1 or 2
                                                           (in each
                                                            column)

       Enter 1 (not covered) or 2 (covered) for each
        vehicle type, in this order:  LDGV, LDGT1,  LDGT2,  HDGV
07/91

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                              2-83

                           Table 2.2-5

           SUMMARY OF THE LOCAL AREA  PARAMETER RECORD
Field
1
2
3
Content, Description, Codes

Scenario name
Minimum daily temperature (°F)
Maximum daily temperature (°F)
Format

4A4 , 2X
F5.0
F5.0
Allowable
Values


0.-100.
10. -120.
Refer to
Section

2.2.9
2.2.11
2.2.11
       (These temperatures  are used  in  calculation  of the  diurnal
        index for  evaporative HC  emissions.   If TEMFLG = 1,  they
        are  also used  to  calculate temperatures for correction  of
        exhaust HC,  CO, and NOx,  hot soak  evaporative, refueling,
        resting loss,  and running loss  emissions.)


       "Period  1"  RVP  (psi)          F5.l     7.0-16.0     2.2.12

       (Average fuel volatility for  the area  being  modeled,  applied
        to years of  evaluation prior to the  "Period 2" start year)


       "Period  2"  RVP  (psi)          F5.1,1X  7.0-16.0     2.2.13

       (Average fuel volatility for  the area  being  modeled,  applied
        to years of  evaluation at or after "Period  2" start  year)


       "Period  2"  start year          12      89-99,00-20    2.2.13

       (Last 2  digits  of  first calendar year  for  which  "Period  2"
        RVP  is  assumed; base RVP  applies for  years  of evaluation
        prior to the year specified)


       Oxygenated  fuel flag           IX,II      1 or 2       2.2.14

       (Flag indicates whether effect of oxygenated fuels  on
        exhaust CO is  to  be modeled; if missing,  assumed to  be  "1")


       Diesel  sales  fraction flag     IX,II      1 or 2       2.2.15

       (Flag indicates whether user  is  supplying  alternate LDV  and
        LDT  diesel sales  fractions;  if  missing,  assumed  to be "1")
07/91

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                               2-84

                          Table  2.3-1

               SUMMARY OF THE  SCENARIO RECORD(S)


Record 1:  Scenario Descriptive Record  (MANDATORY)

                                                Allowable  Refer to
Field  Content, Description, Codes    Format      Values    Section
       Region for which emission      II,IX      Ior2       2.3.1
        factors are to be calculated

        1 = low-altitude
        2 = high-altitude


       Calendar year of evaluation    12,IX       60-99,      2.3.2
                                                  00-20
       (Last 2 digits of calendar year for which emission
        factors are to be calculated, as of January 1)


  3    Average speed to be used in              2.5-65.0      2.3.3
        emission factor calculations

       If SPDFLG = 1,                   F4.1
        one speed is used for
        all vehicle types
                                         or

       If SPDFLG = 2,                 8(F4.1,1X)
        eight speeds are used,
        one for each vehicle type,
        in this order:
        LDGV, LDGT1, LDGT2, HDGV, LDDV, LDDT, HDDV, MC
  4    Ambient temperature  (°F)       1X,F4.1   0.0-110.0     2.3.4
        (If TEMFLG = 2, ambient temperature is. used to correct
        exhaust, hot soak evaporative, resting  loss, and running
        loss emission factors fortemperatures other than 75°F)
 07/91

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                               2-85

                     Table 2.3-1  (continued)

                SUMMARY OF THE SCENARIO RECORD(S)


Record 1:  Scenario Descriptive Record  (MANDATORY)"* (continued)

                                                Allowable  Refer to
Field  Content, Description,  Codes     Format     Values    Section


  5    Operating mode fractions     3(1X,F4.1)  0.0-100.0     2.3.5
       [Percent of VMT accumulated by (1) non-catalyst vehicles
        in cold-start mode (PCCN), (2) catalyst-equipped vehicles
        in hot-start mode (PCHC), and (3) catalyst-equipped
        vehicles in cold-start mode (PCCC)]
Record 2:  LAP record for this scenario only (OPTIONAL)
(required only if LOCFLG = 1)	

                          See Table 2.2-5
Record 3:  Oxygenated fuels descriptive record (OPTIONAL)
(Required only if OXYFLG = 2 on LAP record, and LOCFLG = l)
Field
1
2
Content, Description, Codes
Ether blends market share
Alcohol blends market share
Format
F4.3,1X
F4.3,1X
Allowable
Values
0.0-1.0
0.0-1.0
Refer to
Section
2.3.9
2.3.9
  3    Average oxygen content of
        ether blend fuels  (by wgt)    F4.3,1X   0.0-0.027    2.3.9

  4    Average oxygen content of
        alcohol blend fuels  (by wgt)  F4.3,1X   0.0-0.035    2.3.9

  5    RVP waiver switch (indicating
        whether oxygenated fuels are
        allowed to exceed  regulated
        RVP  limit by 1.0 psi)         IX,II      1 or 2      2.3.9


 1   NOTE:  Values MUST  be entered  for  all fields  in  the scenario
    descriptive  record;  there  are  NO DEFAULT  VALUES  for  these
    variables.
 07/91

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                               2-86

                     Table 2.3-1  (continued)

                SUMMARY OF THE SCENARIO RECORD(S)


Records 4-6:  Diesel sales fractions (OPTIONAL)
(Required only if DSFLAG = 2 on LAP record and LOCFLG =1)

                                                Allowable  Refer to
Field  Content, Description,  Codes    Format      Values    Section
Three records listing fraction of
LDV/LDT sales by model year that
were diesel, starting with model
year = calendar year of evaluation

20F4.3
20F4.3
10F4.3

0.0-1.0
0.0-1.0
0.0-1.0

2.3.10


Record 7:  VMT mix by vehicle type record (OPTIONAL)
(Required only if VMFLAG = 2)	

                                                Allowable  Refer to
Field  Content, Description, Codes    Format      Values    Section

 1-8   VMT fraction accumulated by    8F4.3      0.0-1.0      2.2.2
        each of eight vehicle                                  and
        types, in this order:                                 2.3.6
        LDGV, LDGT1, LDGT2, HDGV,
        LDDV, LDDT, HDDV, MC


Record 8:  Additional Correction Factor record (OPTIONAL)
(Recruired only if ALHFLG = 2 or 3)	

                                                Allowable  Refer to
Field  Content, Description, Codes    Format      Values    Section

  1    Air conditioning use fraction  F4.2       0.0-1.0    2.3.8.3
                                                             and
        (Percent of AC-equipped                             2.3.8.7
         vehicles actually using AC)  	

Note:  If  ALHFLG  =  2,  no  AC  usage  correction  factor will  be
       applied, and the input value of this variable should be 0.0.

       If ALHFLG  =  3,  the input value is  overridden  by calculated
       value   (see  2.3.8.7);  however,  a  nonzero value  must  be
       entered  here  in  order   to   have  the  correction  factor
       calculated and applied.
07/91

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                               2-87

                     Table 2.3-1  (continued)

                SUMMARY OF THE SCENARIO RECORD(S)


Record 8:  Additional  Correction Factor record (OPTIONAL)
(Required only if ALHFLG = 2 or 3)	(continued)

                                                Allowable  Refer to
Field  Content, Description,  Codes    Format      Values    Section

 2-4   Extra load fractions           3F4.2     0.0-1.0     2.3.8.4

       (Percent of vehicles assumed to be carrying additional
        500 Ib; fractions apply to LDGVs, LDGTls, and LDGT2s,
        in that order)
5
or
5-7

Trailer towing fraction(s)

(Percent of vehicles assumed
to be towing trailers)
F4.2
or
3F4.2

0.0-1.0 2.3.8.5



Note:  If ALHFLG = 2, one value is required and is used to
        calculate correction factor for all three vehicle types.

       If ALHFLG = 3, three values are required and are used to
        calculate correction factors for LDGVs, LDGTls,
        and LDGT2s, in that order


  6    Absolute humidity level        F4.0      20.-140.    2.3.8.6
or 8                                  	

       (Grains water per pound dry air, used to
        correct exhaust NOx emission factors)


9, 10  Dry and wet bulb temperatures  2F4.0     0.-110.     2.3.8.7
       in °F                          	

       If ALHFLG = 3 only, these temperatures  are used to
        calculate a "discomfort index," which  in turn is
        used to estimate an A/C usage fraction (which then
        overrides the value input in Field 1 of this record).
 07/91

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                                2-88

                           Table 2.4-1

         SUMMARY OF THE MOBILE4.1  INPUT RECORD SEQUENCE
Input Record Sequence

1 PROMPT flag record
(1-3 IOUNEW values)*
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
PROJID
TAMFLG
SPDFLG
VMFLAG
MYMRFG
NEWFLG
IMFLAG
ALHFLG
ATPFLG
RLFLAG
LOCFLG
TEMFLG
OUTFMT
PRTFLG
IDLFLG
NMHFLG
record
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
flag record1
1 HCFLAG flag record1

(24 or 48 tampering records)2
     jif TAMFLG = 2
(1 VMT mix record)
     if_ VMFLAG = 3
(24 mileage accumulation rate by age records)
     if MYMRFG = 2 or 4
(24 registration distribution by age records)
     if_ MYMRFG = 3 or 4
(1 to 100 basic emission rate records)
     Lf NEWFLG = 2
(1 I/M program descriptive record)
     ijf IMFLAG = 2
(1 ATP descriptive record)
     rf ATPFLG « 2
(1 or 2 refueling VRS descriptive records)3
     ij: RLFLAG = 2, 3, or 4
(1 Local Area Parameter record)4
     if LOCFLG = 2
(1 oxygenated fuel descriptive record)
     if LOCFLG = 2 and OXYFLG = 2
(1 trip length distribution record)
     if SPDFLG = 4
(1 by model year inclusion vector record)
     if OUTFMT = 5
Input
Section
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
ONE-TIME
Refer to
Section
2.1.1
2.1.2
2.1.3
2.1.4
2.1.5
2.1.6
2.1.7
2.1.8
2.1.9
2.1.10
2.1.11
2.1.12
2.1. 13
2.1.14
2.1.15
2.1.16
2.1.17
2.1.18
2.1.19
2.2.1
2.2.2
2.2.3
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.3.9
2.3.11
2.2.16
07/91

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                               2-89

                      Table 2.4-1 (continued)

          SUMMARY OF THE MOBILE4.1 INPUT RECORD SEQUENCE

                                                  Input     Refer  to
Input Record Sequence                           Section     Section


1 Scenario descriptive record                  SCENARIO       2.3.1
(1 Local Aera Parameter record)4
     if_ LOCFLG = 1                             SCENARIO       2.2.8
(1 oxygenated fuel descriptive record)
     if_ LOCFLG = 1 and OXYFLG = 2              SCENARIO       2.3.9
(3 diesel sales fraction by model year records)
     if_ LOCFLG = 1 and DSFLAG = 2              SCENARIO     2.3.10
(1 VMT mix record)
     if_ VMFLAG = 2                             SCENARIO       2.2.2
(1 trip length distribution record)
     jj[ SPDFLG = 3                             SCENARIO     2.3.11
(1 additional correction factor record)
     if ALHFLG = 2 or 3                        SCENARIO       2.3.8
     Required  only if  reassignment  of  output  device  numbers is
     desired.
     These  16  flags   are   entered  on   one  record  (format  II,
     15(1X,I1)) if PROMPT = 3 or 4.
     24 records if IMFLAG = 1; 48 records if IMFLAG = 2.
     Stage II  record  if RLFLAG  = 2; onboard record  if  RLFLAG = 3;
     both records if RLFLAG = 4.
     The  Local  Area  Parameter  record must  appear  in   either  the
     One-Time or the Scenario data section.
07/91

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                               2A-1


                           Appendix 2A

             INSPECTION/MAINTENANCE AND ANT I-TAMPER ING
                 PROGRAM TERMINOLOGY DEFINITIONS


     This  appendix  discusses  the terminology  used  to  describe
inspection and maintenance (I/M)  and anti-tampering  (ATP)  programs
for purposes  of modeling  the  emission  benefits of  such  programs
using  MOBILE4.1.    In general,   MOBILE4.1  assumes  that  the  I/M
program is mandatory, periodic,  and  covers a well-defined group of
vehicles.  There are many details (e.g.,  instrument specifications)
which  are beyond  the scope  of  this  document.   Program  planners
should consult with  EPA  (Technical Support Staff, 313/668-4367 or
FTS  374-8367)  if   there   are  questions   regarding  I/M  program
requirements.


2A.1   I/M PROGRAM TERMINOLOGY

2A.1.1   I/M

     I/M  refers to   "inspection  and  maintenance" programs,  which
are  inspections  of  vehicles  using  a  measurement  of  tailpipe
emissions  and  which  require  that  all  vehicles  with  tailpipe
emissions higher than the  program cutpoints be repaired to  pass a
tailpipe  emission  retest.   Inspections  that are aimed at verifying
the presence and proper connection of emission control devices and
components   are  termed   anti-tampering   programs   (ATPs).    For
convenience, such  tailpipe I/M and ATPs are  sometimes  referred to
collectively simply  as "I/M programs" in other EPA documents.


2A.1.2  Start Year

     The  year  in which the  periodic inspection  program  begins to
require  both  inspection   and  repairs   is  called  the  start  year.
MOBILE4.1 only provides for a  January 1st  start  date.   Other start
dates  will  require   interpolation  between two  MOBILE4.1  runs to
give accurate estimates of benefits.  Separate and different start
dates  may be specified for a tailpipe I/M program and an ATP.


2A.1.3 Stringency

     Stringency refers to  the tailpipe  emission  test  failure  rate
expected  in  an I/M program  among  pre-1981  model  year  passenger
cars   or  pre-1984  light-duty  trucks,  based on  the  short   test
emission  cutpoints.   The  expected failure rate  can be determined
by applying the program  cutpoints to  a representative  sample of
 07/91

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                               2 A-2

vehicles tested in  a survey.  Actual  failure rates reported  by a
program can  also be used to  determine stringency, but  only  when
there is  no  possibility of  significant testing or  data  reporting
errors.   MOBILE4.1  assumes that the failure  rate  remains fixed at
the stringency level for each  evaluation year.   MOBILE4.l does not
allow a stringency less than 10% or greater than 50%.


2A.1.4  First Model  Year

     The first model year  refers to the oldest  model  year vehicle
which  is  always  included  in the  inspection  program.   MOBILE4.l
assumes that all vehicle classes have  the  same  model year coverage
and does not  allow  for a separate coverage period for each vehicle
class.  Some  programs  do  not  fix the  model  years covered  by the
program,  and  instead   use  a  coverage  "window"  to  define  which
vehicles must be inspected.  For example,  such  a program  may cover
only  vehicles  15 years old or  younger.   Such  programs  cannot be
modeled accurately using MOBILE4.1 without special assistance.


2A.1.5  Last Model  Year

     The  last model  year  refers  to  the  youngest  (newest)  model
year  vehicle  which   is  always  subject  to  the  inspection program.
This  allows  for a  program  to cover  only particular  model years.
Most  programs  routinely  include new  model  year  vehicles  in the
program as they  reach  one year of age.  It is recommended that the
maximum allowable  last  model  year  (2020) be   input  as   the   last
model  year,   unless a  special  case   requires  some  other  input.
MOBILE4.1's  calculation   of   I/M   credits  already  assumes   that
vehicles  less  than  one year  old are  exempt from  inspection, so
input   of   the  maximum   last  model   year  allows   for  maximum
flexibility.


2A.1.6  Waiver Rates

     Many I/M  programs waive  the  requirement to pass a  retest if
certain defined  criteria  are  met.  Waivers  are  often  granted in
I/M  programs  for  vehicles  whose  owners  have  spent  over  a  set
dollar  limit  in attempting  to  comply  with  the  program  retest
requirement.

     The  waiver  rate   inputs  to  MOBILE4.1   reduce  the  estimated
benefit of  the  I/M program design.   The waiver  rates  are always
calculated  as a percent  of  non-duplicate initial  test  failures.
Waiver  rates  must be provided for pre-1981 and for  1981  and later
model year  light-duty  vehicles.   MOBILE4.1   assumes that tampered
or  misfueled  vehicles cannot  receive waivers,  and  so   does  not
reduce  the ATP benefit based on the waiver rate.
07/91

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                               2A-3
2A. 1.7  Compllance Rate

     Compliance  rate  refers to  the  level  of compliance  with the
inspection program.   For  example, assume  a program  required  that
all  passenger  cars  be  inspected  each year,  and  that  100,000
passenger  cars  were  registered  in  the   area   covered   by  the
program.  If  in a given year only 95,000  passenger  cars completed
the  inspection  process  to  the  point  of  receiving   a  final
certificate  of  compliance or waiver, it could be  assumed  that the
remaining 5,000  vehicles  had avoided the  inspection requirement.
The  compliance  rate  for  this   program  would  then  be 95%.   The
number of initial  inspections should not be used  to  calculate the
compliance rate, since some cars may drop out after failing one or
more tests.   The compliance rate input is also used  to account for
vehicles  which  are  waived from  compliance  without  any testing
(e.g., vehicles with special testing  problems  or  vehicles  owned by
certain types of owners).

     MOBILE4.1  uses a  single  compliance  rate to reduce  both the
I/M  and ATP portions  of  the program benefits.   The  reduction in
benefit  is  not linear.  The benefit  loss  per  vehicle assumes that
the  failure  rate among non-complying vehicles will be  larger than
the   expected   failure  rate  in  the   fleet.    As   the  rate  of
non-compliance   increases,  the  non-complying  failure  rate  will
approach and finally equal  the expected  failure rate.

     The following  table  shows  the loss of benefit assumed for the
enforcement  fraction:
Compliance
   Rate

   100%
     99%
     98%
     97%
     96%
     95%
     90%
     85%
     80%
     75%
     70%
     50%
   Non-
Compliance
   Rate

    0%
    1%
    2%
    3%
    4%
    5%
   10%
   15%
   20%
   25%
   30%
   50%
Non-Complier
Failure Rate
 Adjustment
2
2
2
2
2
1
1
1
1
1
1
.0
.0
.0
.0
.0
.5
.4
.3
.2
.1
.0
    1.0
Fraction
Benefit
  Loss

  .000
  .020
  .040
  .060
  .080
  .095
  .169
  .238
  .302
  .361
  .415
  .615
Fraction
 Benefit
Remaining

  1.000
   .980
   .960
   .940
   .920
   .905
   .831
   .762
   .698
   .639
   .585
   .385
 2A.1.8   Inspect i on  Frequency

      MOBILE4.1  allows  for two  inspection  frequencies.    "Annual"
 means that all covered vehicles must be  inspected once each year.
 07/91

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                               2 A-4

"Biennial"  means  that  each vehicle  is  inspected  once  every  two
years,  such that half  of  the  vehicles  of  each  model  year  are
inspected  each  calendar   year.    Any  other  inspection  frequency
would require alternate I/M credits provided by EPA.


2A. 1.9  Vehicle Classes

     MOBILE4.1 program benefits  are  calculated separately for each
gasoline-fueled vehicle class.   No emission benefits are estimated
for   diesel   vehicles   or   motorcycles.    The   vehicle   class
designations are based on the certification standard definitions:

     LDGV -  light-duty gasoline-fueled vehicles (passenger cars).

     LDGT1  -  light-duty  gasoline-fueled  trucks  less  than  6,000
     Ibs gross vehicle weight (lighter pick-up trucks and vans).

     LDGT2  - light-duty gasoline-fueled  trucks greater  than 6,000
     Ibs  but less than  8,500  Ibs GVW  (heavier  pick-up  trucks  and
     vans and many commercial trucks).

     HDGV   -  heavy-duty  gasoline-fueled   vehicles  greater  than
     8,500  Ibs  GVW  (heavier commercial  trucks,   including  highway
     hauling trucks).

Many areas  do  not use the  same  vehicle class designations in their
vehicle  registration  data as  are used in MOBILE4.   In  these cases
care must be taken  not to claim  coverage for too many vehicles.


2A.1.10   I/M Test Types

     There  are three I/M  test types allowed  in  MOBILE4. l.   These
test types only  apply to  the  inspection of 1981  and  newer model
year passenger cars  and  1984  and  newer  light-duty  trucks.    (The
concept  of  stringency already takes into account the effect of the
test type  on  the benefits  from older vehicles.)   The  chosen test
type is  assumed to  be applied to  all 1981  and newer passenger cars
and   1984   and  newer  light-duty  trucks  both   at  the  initial
inspection  and the retest.  It  is  assumed  that  the cutpoints used
for  the  inspections are 1.2 percent CO and  220 ppm  HC in  all cases.

      Idle  Test  refers to  a  measurement  of  HC  and  CO emission
     concentrations  of  a  fully  warmed  vehicle   as  it  idles   in
     neutral or park.

     2500/1 die  Test   refers   to  a  measurement   of  HC  and   CO
      emission  concentrations  of a fully warmed vehicle at 2500 rpm
      in  neutral  or  park and again at  idle.   The  vehicle must pass
      both  at idle and at  2500  rpm  in order  to pass  the test.
 07/91

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                               2 A-5

     Loaded/Idle  Test  refers  to  a  measurement  of  HC  and  CO
     emission  concentrations  of  a  fully  warmed  vehicle  on  a
     chassis dynamometer at  a  constant  load,  and again at  idle in
     neutral or  park.   The vehicle  must  pass both  at  idle and at
     load in order to pass the test.


2A.1.11  Alternate I/M Credits

     In  special  cases where  the design of  the  I/M program  to be
modeled does not fit into any of the  categories  defined in MOBILE4
(e.g., semi-annual  or tri-annual  inspection  frequency),  the model
allows the user  to  supply a  set of  factors  that will be  used to
determine  the  I/M program benefits.   Normally  these  factors will
be  supplied  by EPA  at  the request  of  the program  manager  or air
quality planner.


2A.1.12  Centralized Programs

     Centralized inspection programs  refer  to those programs which
completely  separate  the  inspection of  vehicles  from  the repairs.
Usually  high-volume  inspection stations,   run either by  the  local
agency itself  or by  a  contractor, will perform all initial tests
and retests after repair.  Garages  and  other  repair facilities are
not  allowed to  perform official  tests.   Independent,  centralized
programs are the standard used to determine  the emission benefits
for I/M  and ATP program designs.


2A.1.13  Decentralized Programs  (Manual)

     Decentralized  inspection  programs  refer  to   those  programs
where  the  local  program  agency  licenses  service stations  and
garages  to  perform  official  inspections and  reinspections.  These
licensed inspection  stations  are allowed  to perform repairs on the
vehicles   they  inspect.    The  number  of   licensed  inspections
stations  in decentralized programs  is larger  and  the volume per
station  is smaller than for centralized programs.

     Decentralized programs  have been  found  to  be  less  effective
than  centralized programs.   As  a  result,  MOBILE4.1  reduces the
emission benefits, relative to  a centralized  program design,  by 50
percent  for  the I/M (tailpipe test)  portion  and  50 percent for the
ATP portion of  the  program  if  a  decentralized  design  is chosen.
The  50 percent reduction in benefits from the tailpipe portion of
the test includes the  loss  due to  waivers,  if   any.   Areas  which
can   demonstrate that   a  currently  operating  network   achieves
greater  emission reductions should  contact EPA for assistance.
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                               2 A-6

2A.1.14  Computerized Inspection

     Some   decentralized   I/M  programs   require   the   use   of
computerized  emission  analyzers.   These  analyzers  contain  small
computers which  keep track  of  all  official  inspection  activity,
automatically  calibrate   the   instrumentation,   and   prompt   the
inspector  during  the   inspection procedure.   The  computer  also
prepares a machine-readable record of  all  official  inspections and
calibrations,   and  will   not   allow  inspections  whenever   it
determines the instrumentation to be out of calibration.

     MOBILE4.1  assumes  that  the  I/M  portion of  a  decentralized
computerized  inspection program  will  be 50 percent as effective as
a centralized program of similar  stringency  (i.e.,  the  benefits of
the program  are discounted by 50 percent).    As noted  above,  this
benefit reduction  includes  the impact  of  waivers,  if  any,  and is
not  applied  on  top  of  a  waiver-related  loss potential  benefits.
Any area  that  has  data  to support  the contention that  a specific
decentralized  computerized  program  is  more  efficient  than  this
(i.e.,  that  the program should  have its benefits  discounted  by
less  than 50  percent  relative  to the  benefits  of  a  centralized
program)  is  encouraged  to  contact EPA for assistance  in verifying
that  contention  and  in  modeling the  impact  of that  program on the
in-use  emission factors.   Decentralized  computerized   inspection
programs  will  also have the  benefits from  the ATP  portion of the
program reduced by 50 percent.


2A.1.15  Tech  I-I I  and Tech IV+

     The  calculation  of  I/M  benefits  for   MOBILE4  was  done  by
technology group,  which can  roughly  be  determined  by  model  year
for  each vehicle  type.   These  technology groups  have  come  to be
referred to  by numbers.   Within the Tech  IV  group,  I/M credits are
developed separately for  each model year of LDGVs, with  model year
mapping   to   LDGTs  based   on  similarity  of  emission  control
technology   used.    The   table  below  summarizes  the   technology
groupings  used  in MOBILE4.1   and  their respective  application to
gasoline-fueled passenger cars and light trucks.

         Technology    	Model Years Covered	
          Grouping       LDGV          LDGT1         LDGT2

               I        Pre-1975      Pre-1975      Pre-1979
              II        1975-80        1975-83       1979-83
              IV+         1981+          1984+         1984+

      Sets of alternate  I/M credits may contain both  Tech I and II
credits,  only Tech  IV+ credits,  or   Tech  I,  II,  and  IV+ credits
together.   This is usually  indicated in the  header  block  of the
alternate I/M credit deck.
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                               2 A-7

2A.2  ATP TERMINOLOGY

     This section  discusses  the terminology  used to describe  ATP
inspections for purposes  of  modeling  the emission benefits of such
programs  using MOBILE4.1.   In  general,  it  is  assumed that  the
program is mandatory,  periodic,  and covers  a well-defined group of
vehicles.  A  program  which  inspects for  tampering only when  a
vehicle  has  failed  its  tailpipe  I/M inspection,  or  only when  a
vehicle owner  requests a  test waiver, is not considered as an  ATP
in MOBILE4.1.

     It  is also assumed that  the  inspections are primarily visual
rather   than   functional,   and   involve   no   disassembly   or
disconnection  to  gain access  to  hidden  components   (other  than
removal  of  the  gas  cap  to  view  the  fuel  inlet  restrictor).
However,  program  planners  are encouraged  to  define   failure  in
broad enough terms of visual  damage and  proper operating condition
so that  any  emission control component determined by the inspector
to be  non-functional can  be properly failed  and repaired.   There
are  many  details  (such   as  replacement catalyst  specifications)
which  are beyond the  scope  of this  discussion.   Program planners
should  consult  with  EPA1s   Office  of  Mobile .Sources   (Technical
Support   Staff,   313/668-4367  or   FTS  374-8467)   if   there  are
questions regarding  the requirements of ATP inspections.


2A.2.1  ATP

     Anti-tampering  programs  (ATPs)  are  periodic  inspections  of
vehicles  to   detect  damage  to,  disablement  of,   or   removal  of
emission  control  components.  Owners  are  required to  restore  the
vehicle's   emission  control   system   and   have  the  vehicle
reinspected.    Note that programs  that  inspect for  tampering only
those  vehicles failing an I/M tailpipe test  are  not considered for
MOBILE4.1 modeling purposes  to have an ATP,  and should  not attempt
to derive ATP  emission reduction credits.


2A.2.2  Tampering  and Misfueling

     Any  physical  damage to,  or  disablement or  removal of,  an
emission  control  component  is  considered  tampering in  MOBILE4.1.
This  does not  limit tampering only  to  deliberate disablements or
only  to  those disablements  of  which the vehicle  owner is aware.
As  a result,  tampering can  often  be  a result  of poor   maintenance
as  opposed  to  some  action  by the  vehicle  owner  or  a service
mechanic.

     Misfueling is the use of  leaded fuel  in any vehicle which is
equipped  with  a  catalytic  converter.   This includes   inadvertent
use  of  leaded  fuel without the knowledge of the vehicle  owner.
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                               2 A-8

2A.2.3  Air Pump Inspection

     Air  pump  systems  supply  fresh  air needed  by the  catalytic
converter  to  reduce  engine  emissions  before   they   leave  the
tailpipe.  Inspectors should  check  for  missing belts and hoses and
proper connection  at the exhaust  manifold.   Sometimes  the  entire
pump  and  its plumbing are  removed.   A valve  is  sometimes  used to
route air  away from  the  exhaust  stream  during  certain  operating
modes.   This valve  should be  checked  for proper  hose and wire
connections.    Often  the   air   is  injected  directly   into  the
catalytic  converter  underneath   the  vehicle.    If    so,   this
connection should  be checked.   Any  missing,   damaged  or  altered
components of the air pump system should be replaced.


2A.2.4  Catalyst Inspection

     The catalytic converter, sometimes  referred  to simply  as the
catalyst, oxidizes excess  hydrocarbon  and  carbon  monoxide from the
engine  exhaust into  water and  carbon  dioxide.   Newer  catalysts
also  reduce  oxides of nitrogen  in the exhaust.   The metals which
accomplish  this  task  are  most  commonly  coated  on  a  ceramic
honeycomb  inside  the stainless steel  shell of the  catalyst.  The
catalyst  resembles  a muffler  in  some ways, but  would  not  be
confused  with  a  muffler  because  it   is  farther  forward   on the
vehicle, and its stainless steel shell will not rust.

     Some cars will  have  more than one catalyst,   so the  number of
catalysts  expected  should  be   determined  before  the  inspection
begins.   Some   catalysts   are   located  very  near the  exhaust
manifold,  so  the  inspector  should be  sure  to  check  the  entire
length  of the  exhaust  piping  from the  exhaust  manifold   to the
muffler before determining that the catalyst is not  present.

     Emission  credit should not  be claimed using MOBILE4.1  unless
regulations  provide   a mechanism to  assure that  failed cars are
correctly  repaired with  OEM  or  approved aftermarket replacements.
Program  planners  should  consult  with  EPA to   avoid  incorrectly
claiming credit.


2A.2.5  Fuel Inlet Restrictor Inspection

     Vehicles  requiring  the  use  of  only  unleaded gasoline have
been  equipped  with fuel  inlets that only allow use  of  narrow fuel
nozzles.  Leaded  fuel is  required to be dispensed only  from pumps
using wider  nozzles.  Any vehicle found to have  a fuel inlet which
allows  a leaded fuel nozzle  to  be inserted,  such  as  having the
nozzle  size  restriction  removed,   is  assumed  to  have  used  leaded
fuel.    Leaded  fuel permanently  reduces   the   ability  of  the
catalytic  converter  to   reduce  emissions.   Therefore,  vehicles
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                               2A-9

found with  a fuel  inlet  which allows  insertion  of a  leaded  fuel
nozzle should be required  to  replace the catalytic  converter.   In
addition, the  vehicle's  fuel  inlet should  be  repaired  to  only
allow the insertion of unleaded fuel nozzles.

     Repair  of the  fuel  inlet restrictor only is not  considered a
repair which will  reduce  the  emissions  of the vehicle.  The damage
to the emission control of the vehicle occurs  in  the catalyst.   It
is  the   catalyst   which  must  be  replaced  to   result   in   any
substantial   emission  reduction.    The   inlet  restrictor  must  be
replaced simply as protection for the new catalyst.

     MOBILE4.1  assumes that  inspectors  are   not  allowed  to  skip
this  inspection  for  such reasons  as  that  the  fuel  inlet  is
concealed by a locked door.


2A.2.6  Tailpipe Lead Detection Test

     Leaded fuel permanently  reduces the ability of  the catalytic
converter  to   reduce   engine  emissions  before  they  leave  the
tailpipe.   Therefore,  vehicles  found  to  have  used   leaded  fuel
should  be required  to replace  the catalytic converter.   EPA has
allowed  for the  use  of  a   lead  detection  test   in   the  vehicle
tailpipe  as a  method to detect the use of leaded fuel.  Since this
is a chemical  test,  care must be taken  to  assure that the test is
properly  conducted and that the results are properly interpreted.

     Vehicles  with evidence  of  lead deposits  in  the tailpipe have
used  leaded fuel.   The  damage to the  emission  control  of  the
vehicle  occurs  in  the catalyst.  It is  the  catalyst which must be
replaced  to result  in any  substantial  emission reduction.   (The
tailpipe  should also be replaced simply  to  avoid failing the test
at the  next  inspection.)  ATPs  which  require failure  of  both the
fuel  inlet  restrictor  inspection  and the  tailpipe lead detection
test  before  requiring replacement  of  the catalyst  get credit for
neither  in  MOBILE4.1,  and should not indicate either  inspection on
the input records.


2A.2.7   EGR Inspection

     The  exhaust  gas  recirculation  (EGR)  system reduces oxides of
nitrogen  by  routing  some  of  the   exhaust  back into  the  intake
manifold.   The primary component of the system  is  the valve which
controls  the   flow  between  the   exhaust  and  intake manifolds,
however,  most  systems are  quite complex with various sensors and
valves  which  control  the  operation of  the  system.   Hoses  may be
plugged,  either deliberately or by neglect.  Any  system observed
with  missing  or damaged  components or misrouted or plugged hoses
and wires should be  failed and  repaired.
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                              2 A-10

2A.2.8  Evaporative Control  System

     The evaporative control  system  collects gasoline  vapors  from
the gas  tank and  carburetor bowl  and stores  them in  a  charcoal
canister.   During certain engine  operations, the  canister  purges,
releasing the vapors which  are  routed to the engine to be  burned.
In  addition  to  the  evaporative  canister  itself,   the   system
includes  varying  numbers  of hoses,  wires  and  control  valves.
Hoses  may be  plugged,  either  deliberately  or  by neglect.   Any
system observed with missing  or  damaged  components or  misrouted or
plugged hoses   and  wires  should be   failed and  repaired.   This
inspection  flag is not  used to indicate  any functional purge or
pressure  testing  of  the  evaporative  emission  control  system.
Emission reductions resulting from such  testing must be calculated
separately.


2A.2.9  PCV Inspection

     The  positive   crankcase  ventilation  (PCV)  system  routes  the
vapors from the crankcase to the intake manifold  where  they can be
burned  by the  engine.   The PCV system  has  two major  loops.   The
most  critical   connects  the  crankcase with  the  throttle  or  the
intake manifold with a hose and usually contains a valve.   Another
hose  connects  the  crankcase with the air cleaner  to  provide  the
crankcase  with  filtered  fresh air.   Any  system  observed  with
damaged or missing  components or with hoses  misrouted  or  plugged,
should be failed and repaired.


2A.2.10  Gas Cap Inspection

     Gas  caps  are  actually  part   of   the  evaporative  control
system.   Without  a  properly operating gas  cap,  fuel  vapors  from
the gas  tank would escape.   On  some  vehicles,  a missing  gas  cap
will   also   cause  the   evaporative   system  canister   to  purge
incorrectly.   Inspectors should examine  the  fuel  inlet   area  of
each  vehicle  to determine  that  the  gas  cap is  present.   If  not,
the vehicle should be  failed and the  gas  cap replaced.   Inspectors
should  not  be  allowed  to skip this inspection  for  such reasons as
that the fuel inlet is concealed by a  locked door.
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                            Chapter 3

                        MOBILE4.1  OUTPUT

3.0  INTRODUCTI ON

     MOBILE4.1   produces   three   types   of  output:    prompting
messages, diagnostic messages, and formatted reports.

     Prompting  messages  are   provided   by  MOBILE4.1   on  tape
(mainframe version)  if the  user  sets  PROMPT =  2 or  4  (section
2.1.1).   These   messages  prompt  the user  to  provide  MOBILE4.1
input  data  in   the  proper  sequence.   There are two  prompting
formats:   vertical  input  (PROMPT  =  2)  and  horizontal  input
(PROMPT  =  4).   Otherwise the prompting messages  are  identical in
both cases.  Prompting messages are discussed in section 3.1.

     Diagnostic  messages  are  used to caution the  user  concerning
user-supplied data.   Three types of diagnostics  exist:   errors,
warnings,  and  comments.  An  error  will  in  all   cases  terminate
processing  of  the  current  scenario,   and  in  some  cases  will
terminate  processing of  the  entire  run.   Warnings  and  comments
are  included to  assist  users  in the interpretation of the results
if MOBILE4.1.  Diagnostic messages are discussed in section 3.2.

     Five  types  of  formatted   reports   can   be   produced   by
MOBILE4.1.   These reports  include  the  information  necessary to
identify  the  scenario being  studied and the calculated  emission
factors  by vehicle type.  The  type of formatted  report  produced
is  controlled  by the  value  assigned to  the OUTFMT  flag  in  the
Control  section  (section  2.1.15).   The  structure of the formatted
report   formats  are  discussed   in   section  3.3,   and  each  is
illustrated in Chapter 5  (MOBILE4.1 Examples).


3.1  PROMPTING MESSAGES

     If  PROMPT = 2 or 4, the user is  prompted  for input  data in
the  order required by  MOBILE4.l.   Prompting  messages are written
to  logical I/O  unit  6,  unless the  user  reassigns the prompting
message  unit  through the IOUNEW  flag (section  2.1.2).   MOBILE4.1
does not prompt  for the first record (PROMPT  flag  and IOUNEW unit
reassignment  record),   since  the   value   of   the  PROMPT  flag
determines whether or not prompting will occur.

     The   prompt  for   each  record  is  described  below.   The
prompting  messages  are  printed  in  boldface   in this  section.
See  the  referenced sections  of Chapter 2 for detailed discussion
of the prompted  values.
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                               3-2


     3.1.1  Control Section Prompts


     3.1.1.1  Title Record Prompt

     The title  record  for the MOBILE4.1  run is  prompted for  by
this message:

                        Enter project id:


     3.1.1.2  16 Remaining Flag Prompts

     If PROMPT  = 2  (vertical  format), the  16  remaining  Control
section flags are prompted for individually,  as  follows:

                       Enter TAMFLG:
                       Enter SPDFLG:
                       Enter VMFLAG:
                       Enter MYMRFG:
                       Enter NEWFLG:
                       Enter IMFLAG:
                       Enter ALHFLG:
                       Enter ATPFLG:
                       Enter RLFLAG:
                       Enter LOCFLG:
                       Enter TEMFLG:
                       Enter OUTFMT:
                       Enter PRTFLG:
                       Enter IDLFLG:
                       Enter NMHFLG:
                       Enter HCFLAG:

     If PROMPT  = 4 (horizontal format),  the 16 remaining Control
section flags are prompted for on one record, with this message:

           Enter TAMFLG, SPDFLG,  VMFLAG,  MYMRFG, NEWFLG,  IMFLAG,
           ALHFLG, ATPFLG, RLFLAG, LOCFLG, TEMFLG, OUTFMT, PRTFLG,
           IDLFLG, NMHFLG, & HCFLAG


     3.1.2  One-time Data Prompts

     Prompts  for One-time Data  section  inputs  have been revised
to  correspond  to  MOBILE4.1  input  requirements.   All  of  the
possible  prompts  for   data   in  the  One-time  Data  section  are
presented below.


     3.1.2.1  Tampering Rate Prompts

     If  TAMFLG=2,   the  replacement  zero-mile  tampering  rates
(ZMLTAM)  and  increases in tampering with accumulated  mileage,  or

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                               3-3
tampering rate  deterioration  rates (DRTAM)  are  asked for  by one
of  two  possible  pairs  of  prompts,   depending  on  whether  an
inspection and  maintenance  (I/M) program  is to  be  assumed  (see
section 2.1.9).   The  input requirements are  discussed in section
2.2.1.  If IMFLAG = 1, then these prompting messages are used:

           Enter tampering intercepts (zero-mile  levels)
            for non-l/M case only:

           Enter tampering slopes (deterioration  rates)
            for non-l/M case only:

If IMFLAG = 2, then these prompting messages are  used:

           Enter tampering intercepts (zero-mile  levels)
            for non-l/M and I/M cases:

           Enter tampering slopes (deterioration  rates)
            for non-l/M and I/M cases:


     3.1.2.2  VMT Mix Record Prompt

     If VMFLAG =  3,  the user  must supply one  alternate vehicle
miles  travelled (VMT) mix record,  which will be  applied  to all
scenarios of  the  MOBILE4  run.   The input required is discussed in
section 2.2.2.  This record is prompted for by the message:

                         Enter VMT split:


     3.1.2.3  Annual Mileage Accumulation Rates and/or
              Registration Distributions by Age Prompts

     If  MYMRFG  =  2,   the  user  must   supply   annual  mileage
accumulation  rates by  age  for  each  of eight vehicle types.  If
MYMRFG  =  3,  the  user must  supply registration distributions  by
age  for each  of   eight  vehicle types.  If  MYMRFG =  4,  the user
must  supply  both, with  the  annual   mileage accumulation   rates
preceding the  registration  distributions.   The input  requirements
are  discussed in  section 2.2.3.   These records are  prompted for
with  the following messages  (first  block   applicable  to annual
mileage    accumulations,    second    block    to     registration
distributions):
Enter
Enter
Enter
Enter
Enter
Enter
MYM
MYM
MYM
MYM
MYM
MYM
ages
ages
ages
ages
ages
ages
1
11
21
1
11
21
-10
-20
-25
-10
-20
-25
for
for
for
for
for
for
LDGVS
LDGVS
LDGVS
LDGT1
LDGT1
LDGT1
S
s
S
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                               3-4
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter

                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
                Enter
MYM ages  1-
MYM ages 11-
MYM ages 21-
MYM ages  1-
MYM ages 11-
MYM ages 21-
MYM ages  1-
MYM ages 11-
MYM ages 21-
MYM ages  1
MYM ages 11
MYM ages 21
MYM ages  1
MYM ages 11
MYM ages 21
MYM ages  1
MYM ages 11
MYM ages 21
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
MYR
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
ages  1
ages 11
ages 21
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for

-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20  for
-25  for
-10  for
-20 for
-25  for
-10 for
-20 for
-25 for
LDGT2s:
LDGT2s:
LDGT2S:
HDGVs:
HDGVs:
HDGVs:
LDDVs:
LDDVs:
LDDVs:
LDDTs:
LDDTs:
LDDTs:
HDDVs:
HDDVs:
HDDVs:
MCs:
MCs:
MCs:

LDGVS:
LDGVS:
LDGVS:
LDGT1s:
LDGT1s:
LDGT1s:
LDGT2S
LDGT2S
LDGT2S
HDGVs:
HDGVs:
HDGVs:
LDDVs:
LDDVs:
LDDVs:
LDDTs:
LDDTs:
LDDTs:
HDDVs:
HDDVs:
HDDVs:
MCs:
MCs:
MCs:
     3.1.2.4  Alternate BER Prompts

     If NEWFLG  = 2,  the  user must  supply  one or more  alternate
basic  emission  rate  (BER)  records.   The  input requirements  are
discussed  in  section  2.2.4,  and  are  summarized in  Table  2.2-1.
These records are prompted for with the messages:
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                               3-5


           Enter no.  of new e.f.  intercept/slope pairs:

           Enter region,  veh.  type,  pollutant,  first my,
            last my,  intercept,  slope,  & above  50K miles  slope:

The second  message  is repeated  as  many times  as  required,  based
on the number entered in response to the first  prompt.


     3.1.2.5  I/M Program Parameter  Record Prompt

     If IMFLAG  =  2,  the user  must supply  a  record specifying the
characteristics of the inspection and  maintenance  (I/M)  program
to be  modeled.   The input  requirements are discussed in  section
2.2.5 and are  summarized in Table  2.2-2.  The   I/M  parameters are
prompted for by this message:

     Enter the  I/M Program parameter record:

         Program  start  year,  stringency,  first  and  last  model
         year  getting  benefits,   old  tech waiver  rate,  new tech -
         waiver  rate,  compliance rate,  frequency  of  inspection,
         vehicle  classes  covered,  test  type,  flag  for  alternate
         I/M  credits,  Tech I &  II  and  Tech IV+,  the format is:
         (4(I2,1X),2(F2.0,1X),F3.0,1X, 11 ,1X, 11 ,1X,4M,1X, 11 ,1X,2I1)

     If the  value of  either  or  both of  the flags  for  alternate
I/M credits  (the  last  two items  of the  I/M  program record)  is 2,
the user must  also  supply alternate I/M  credits to be  read from
logical I/O  unit 4.   MOBILE4.1  does not  issue prompting messages
for the I/M credit data from unit 4.


     3.1.2.6  ATP Parameter Record Prompt

     If ATPFLG = 2,  the user must supply  a  record specifying the
characteristics   of  the  anti-tamper ing  program   (ATP)   to  be
modeled.   The  input requirements  are  discussed  in section 2.2.6
and  are  summarized  in  Table   2.2-3.   The  ATP  parameters  are
prompted for by this message:

     Enter ATP  start year, first & last years  included,
     vehicle types covered, inspection  type & frequency,
     compliance rate, and  inspections conducted
     (format =  3( I2.1X) ,411,1X,F4.0>1X,8M ) :

     The  user  does  not  supply ATP   emission  reduction   credit
matrices   as   input.    MOBILE4.1  contains   a  subroutine  that
generates  these credit matrices  on  the basis  of  the information
supplied characterizing the ATP.
07/91

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                               3-6


     3.1.2.7  VRS Descriptive Record Prompt

     If RLFLAG = 2,  3,  or 4,  the user  must supply  one or  two
records  describing  the  refueling  vapor  recovery  system  (VRS)
requirements to  be modeled.   The  Stage  II VRS record  is  required
if RLFLAG  = 2.   The onboard  VRS record  is  required if  RLFLAG =
3.  Both  records are required  if  RLFLAG =  4,  with the  Stage  II
record preceding the onboard record.  The input  requirements  are
discussed  in  section 2.2.7  and are  summarized  in Table  2.2-4.
The required  record(s)  are prompted  for  by  one  or  both  of  these
messages:

     Enter Stage II VRS parameters - start year,  # phase-in years,
      LOG & HDG % efficiency (12,1X,11,1X,13,1X,13) :

     Enter onboard VRS first model  year
      & vehicle classes (I2,1X,4I1):


     3.1.2.8  LAP Record Prompt

     If LOCFLG = 2,  the user must supply the local area parameter
(LAP) record as part of the One-time data section,  and  it will be
applied to  all  scenarios of the MOBILE4.1 run.   Sections 2.2.8 -
2.2.13 discuss  the  input requirements,   which  are  summarized  in
Table 2.2-5.  The LAP record is prompted for  by this message:

     Enter  scenario  name, min & max  daily  temps,  period 1  and 2
     RVP,  period 2 start year, and OXYFLG:


     3.1.2.9     Oxygenated Fuels Record Prompt

     If the user  has  set OXYFLG  = 2 on  the LAP  record,  then a
record describing oxygenated fuels  in the  area  being modeled must
be supplied.   Section  2.3.9  discusses the input  requirements  for
this record.  The  oxygenated  fuel  record is  prompted for by this
message:

     Enter   MTBE/ETBE    market   share,    gasohol    market  share,
     MTBE/ETBE  oxygen   content,  gasohol   oxygen   content,  gasohol
     waiver flag:


     3.1.2.10  Trip Length Distribution Record

     If the user has  set SPDFLG  = 3 or 4, then a  trip length
distribution  record  must  be  entered  for   use  in  calculating
running loss  emission  factors.  The  input requirements  for this
record  are  discussed   in   section  2.3.11.    The  trip  length
distribution record  is prompted for by this message:

     Enter  trip  length VMT fractions  (6(1X,F4.1)):
07/91

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                               3-7


     3.1.2.11  By Model Year Inclusion Vector

     If  the  user has  set  OUTFMT  =  5,  then a  record describing
which vehicle classes  the  optional  by-model year  emission factor
tables are  requested for  and  whether special information  on I/M
credits and tampering rates and offsets  are  requested.   The input
requirements  for this  record  are  discussed  in  section  2.2.16.
The  by model  year  inclusion  vector  is prompted for  by  this
message:

     Enter vehicle types and I/M and tampering flags,
     format 8I1,2(1X,11)


     3.1.3  Scenario Section Data Prompts

     As  discussed in  section  2.3,  the  Scenario  section consists
of  one to  seven records,  depending  on the  values  assigned  to
flags  in  the  Control  section.   The  first  record,   called the
scenario  descriptive record,  is  mandatory.    The  second  through
seventh  records  are  optional.   All  of the possible data prompting
messages for the Scenario data section are presented below.

     3.1.3.1  Scenario Descriptive Record Prompt

     The   scenario   descriptive  record  specifies  the  region,
calendar   year   of   evaluation,   average   speed(s),   ambient
temperature,  and operating mode  fractions  to be  assumed  for the
current   scenario.   The  input   requirements  are  discussed  in
sections 2.3.1 - 2.3.5,  and are summarized in Table 2.3-1.

     If  SPDFLG  = 1,  a  single  average  speed  is  used   for  all
vehicle types, and the record  is prompted for by this message:

           Enter  region, CY, SPD(1), AMBT, PCCN, PCHC,  PCCC:

     If  SPDFLG  = 2, eight average speeds must  be input,  one for
each of  the  eight modeled vehicle types.  The  record  is prompted
for with this message:

           Enter  region, CY, SPD(8), AMBT, PCCN, PCHC,  PCCC:


     3.1.3.2  LAP Record Prompt

     If  LOCFLG  =1,  a  distinct  local area  parameter  record must
be  supplied  by  the user for each scenario  of the run.  The  input
requirements  are discussed in sections  2.2.8  -  2.2.13,  and are
summarized   in   Table  2.2-5,   The  LAP  record  for  the  current
scenario  is  prompted for by this message:

     Enter  scenario  name,  min & max  daily  temps,  period  1  and  2
     RVP,  period  2 start year, and OXYFLG:
 07/91

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                               3-8


     3.1.3.3  Oxygenated Fuels Record Prompt

     If the  user  has set  OXYFLG  = 2  on  the LAP  record, then  a
record describing oxygenated  fuels  in the area being modeled must
be supplied.  Section 2.3.9  discusses the  input  requirements  for
this record.  The oxygenated fuel record is prompted  for by this
message:

     Enter   MTBE/ETBE   market   share,   gasohol   market   share,
     MTBE/ETBE  oxygen  content,  gasohol  oxygen content,  gasohol
     waiver flag:


     3.1.3.4  Diesel Sales Fraction Prompt

     If the  user  has set  DSFLAG  = 2 on  the LAP  record,  then the
sales  fractions of  LDVs  and  LDTs  that  were  diesel  for the  25
model  years  ending  in  the  calendar  year  of  evaluation  must  be
supplied.    The   input  requirements   are  discussed  in  section
2.3.10.   This  message  is  new in  MOBILE4.1.   The  diesel  sales
fractions are prompted for by this message:

     Enter diesel  sales fractions (LDV/LDT pairs):


     3.1.3.5  VMT Mix Record Prompt

     If VMFLAG  =  2,  a  distinct VMT mix record must be supplied by
the  user  for each  scenario  of the  run.   The  input requirements
are  discussed  in section  2.2.2.   The  VMT mix  for  the current
scenario is prompted for by this message:

                        Enter VMT split:


     3.1.3.6  Trip Length Distribution Prompt

     If the user  has  set  SPDFLG =  3 or  4,  then  a  trip length
distribution  record  must  be  entered   for  use  in  calculating
running  loss emission  factors.   The  input  requirements  for this
record  are   discussed   in  section  2.3.11.   The   trip  length
distribution record  is prompted for by this message:

     Enter trip length VMT fractions  (6(1X,F4.1)):


     3.1.3.7  Additional Light-Duty
              Correction Factor Record Prompt

     If ALHFLG  =  2  or  3,  the user  must  supply  a  record used to
develop and  apply up to four  additional correction  factors to the
light-duty  gasoline-fueled vehicle  and  truck  emission  factors.


07/91

-------
                               3-9


The  input  requirements are  discussed  in  section  2.3.8  and  are
summarized in Table 2.3-1.

     If  ALHFLG  =  2,  six  input  values  are  required,  and  are
prompted for with this message:

              Enter  AC, XLOAD(3),  TRAILR(I),  ABSHUM:


     If  ALHFLG  =  3,  ten  input  values  are  required,  and  are
prompted for with this message:

         Enter AC,  XLOADC3),  TRAILRC3),  ABSHUM,  DB,  WB:
07/91

-------
                               3-10
3.2  DIAGNOSTIC MESSAGES

     3.2.1 Introduction

     This  section describes  the  MOBILE4.1  diagnostic  messages.
MOBILE4.1  issues  three  types  of  diagnostic  messages:    error
messages, warning messages,  and comments.

     Error messages indicate  either  that  invalid input  data were
entered  into MOBILE4.1, or  MOBILE4.1 attempted to perform invalid
operations.  All  error  messages are  prefixed  by ***  Error:.   If
a  number follows ***  Error:,  it  is  the  value read  by MOBILE4.1
for the  variable in error  (the variable name  is  also  printed) .
If  the  error  message  is due  to  an input value  that  is  out of
bounds,  the range of acceptable values is also  printed.   An error
will stop a MOBILE4.1 run.

     The  following  errors  are considered to  be  "fatal"  errors.
If  any   of  these  errors  occur,   no further  processing  of  the
MOBILE4.1 input data will be performed:

           M28, M53, M60,  M61, M82, M89,  M97,  M107, MHO, M121.

     Warning messages  indicate that MOBILE4.l input  data caused
an  operation not necessarily  intended by the user,  although the
situation   is   not   serious   enough  to  be   labeled  an  error.
Nonetheless,   users  should  examine  the  warning  messages  to
ascertain  the  conditions  that were  modeled.   Comments are a type
of  warning message  that  are  printed for the  user's   information.
Neither warning nor a comment will stop a MOBILE4.l run.

     The  following  is  a  list  of  the individual  error, warning,
and comment messages.   In order to  make  the  listing  more useful
to  the MOBILE4.1 user,  all of the messages are  listed by message
number (Mtttt at the  beginning of each message).   MOBILE4.1 prints
the message  number  as part of all  diagnostic  messages, allowing
the user to quickly look up the  message  and  its  explanation in
this  section.     The   diagnostic   messages   are  all  printed  in
boldface in this section.


     3.2.2  Explanation of Messages, Listed by Number  (M##)


M o ***  Error:   Message code  is unknown

     This  message  should  only   be printed   when  the  message
printing subroutine QUITER  is passed an undefined  message code
value.   The run is  aborted at  this  point.   This message  was M88
in MOBILE4.
07/91

-------
                               3-11
M 1 *** Error:    out of bounds for flag 

     This  message  may  be  printed one  or  more times  preceding
message M53  and  program termination.   It will appear  for  each of
the 16 input/output control  flags  which is in error.   The number
appearing  after  "***Error:"  is the  value  of  the  flag  read  by
the program.   Each of  these messages  indicates  the  value  falls
outside of the  valid  bounds  for  that  flag.   This  single  error
message replaces messages Ml through  M16 from MOBILE4.  Allowable
flag values  are listed in  Tables  2.1-1 and 2.1-2.   See  Section
2.1.


M  2 ***  Error:   out of bounds  for  ETBE/MTBE market share
(0. to 1.)

     This  message  is  printed  if  the input  value  of  the market
fraction  of  ether/gasoline  blends is  not  between  zero  and one.
See section 2.3.9.   This message is new  in MOBILE4.1.


M  3 ***  Error:    out  of  bounds for  Gasohol  market share
(0. to 1.)

     This  message  is  printed  if  the input  value  of  the market
fraction  of  alcohol/gasoline blends  is  not  between zero and one.
See section 2.3.9.   This message is new  in MOBILE4.1.


M  4 ***  Error:   out of bounds  for  Total Oxy Fuel market
share  (0.  to 1.)

     This  message  is printed  if  the sum  of the input  values of
the  market   fractions  of  ether/gasoline  and  alcohol/gasoline
blends  is not between  zero  and  one.   See  section  2.3.9.   This
message is new in MOBILE4.1.


M  5  ***   Error:      out  of  bounds  for  ETBE/MTBE Oxygen
Content (0.  to 0.027)

     This message  is  printed if  the input  value  of the  average
oxygen content  of  ether/gasoline  blends  is not  between  0.   and
0.027  (2.7 percent).   See  section 2.3.9.   This  message is new in
MOBILE4.1.
 07/91

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                               3-12
M 6 ***  Error:     out  of bounds for Gasohol Oxygen  Content
(0. to 0.035)

     This message  is printed  if the  input  value of  the  average
oxygen content  of  ether/gasoline blends  is  not between zero  and
0.035  (3.5  percent).   See section 2.3.9.  This message  is  new in
MOBILE4.1.


M  7  ***  Error:    out of bounds for  Gasohol RVP  Waiver  Switch
(1 or 2)

     This message is printed if the input value of  the oxygenated
fuel RVP waiver switch  is  not 1 or 2.   See  section 2.3.9.  This
message  is new in MOBILE4.l.


M a ***  Error:   Inconsistent ETBE/MTBE input encountered

M 9 ***  Error:   Inconsistent Gasohol input encountered

     These  messages  are  printed  if  the   input  values   on  the
oxygenated  fuels record have  internal   inconsistencies  present.
See section 2.3.9.   These messages are new in MOBILE4.1.


M 10 *** Error:  RLFLAG  =   and PRTFLG not = 1 or 4,  so RLFLAG
input  records skipped

     This message  is printed  if  RLFLAG is  set  to   l,  2,  3,  or 4
(meaning that  vehicle   refueling  emission  factors  are  to  be
calculated),  but PRTFLG  is  set  to 2 or  3 (calculate  CO  or  NOx
emission factors only).   See sections 2.1.16 and 2.2.7.


M  11  *** Error:   out  of  bounds  for number  of records to
skip (1  to 999)

     This message is printed when the  user  responds  to the prompt
"Enter  of number  of MOBILE4.1  calls:"  with  a value not  in  the
range  l  to 999.  See Chapter 4 on the PC versions of MOBILE4.1.


M12  ***  Error:    out  of bounds  for number of cold  CO standards
(1  to  2)

M  13  *** Error:    out of  bounds  for  cold CO  standard start
MY (1980-2020)
 07/91

-------
                               3-13
M 14  *** Error:    out  of bounds  for cold  CO standard  #n
(2.0-15.0)

M 15 *** Error:  Cold CO standard #1 must start before #2

M 16  ***  Error:    out of bounds for % IV under CCO std #n
(0.0-100.0)

     Messages  12 -  16  are  printed  when  the user  models  cold
temperature  CO emission  standards  and  includes  values that  are
outside  of  the  allowable  ranges.   This  feature  is  for  EPA
internal use and is not accessible through release MOBILE4.1.


M 17  *** Error:    out  of bounds  for  VMTMIX
(0.  to 1.)

     This  message is  printed if  a value  of  VMTMIX(IV) (vehicle
miles travelled  fraction  for  vehicle  type  IV) is not  between 0.
and 1.  See Section 2.2.2.


M 18  *** Error:   sum of VMTMIX is not equal to 1.

      This  message is printed  if  the sum  of VMTMIX(IV) over  all
vehicle   types  is  not   equal  to  l.    Since  each  VMTMIX(IV)
represents  the  fraction  of  total  miles  that vehicle type  IV
contributes  to the  total  vehicle miles  traveled by the  fleet, the
sum of these fractions should equal 1.   See  Section 2.2.2.


M  19  *** Error:     negative  model  year
mileage

      This message is printed  if  the user supplied mileage accrual
data  (annual  mileage  accumulation rate)  for  model  year  JDX and
vehicle  type  IV is  negative.   All  annual mileage accumulation
rates must be  >.  0.0.   See Section 2.2.3.


M 20 ***  Error:     negative  model year
registration

      This  message   is  printed  if  the  model year  registration
fraction  is  negative.   Since this  number  represents the fraction
of  all  vehicles in the fleet  of a  given age,  it must be between  0
and  1 inclusive.  See  Section 2.2.3.
 07/91

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                               3-14
M 21 Warning:   registration with zero mileage

M 22 Warning:   mileage with zero registration

     One  of  these messages  is printed  if,  for  a  given  vehicle
age, vehicles  either do  not  accumulate mileage  yet  make up  a
fraction of  the  fleet  (M21),  or do not  make  up  a fraction of the
fleet,  but accumulate mileage  (M22).  All  vehicle type/model year
combinations assumed  to exist  in  the fleet  must  accumulate some
mileage annually.  For  a  given vehicle  type and vehicle  age,  if
either the mileage accumulation rate or  the registration fraction
is zero, both should be zero.  See Section 2.2.3.


M 23 ***  Error:    out of  bounds  for e.f.  changes
(1 to 100 pairs)

     This  message is  printed  if  the   number  of   emission  rate
modifications  is  not between 1 and  100.   MOBILE4.1  is limited to
handling a maximum of 100 modifications.   See Section 2.2.4.


M 24 *** Error:  out of bounds for region  (1 or 2)

     This message  is  printed if the region chosen in the scenario
record  is  not  equal  to 1  (low altitude)  or 2  (high altitude).
See Section  2.3.1.


M 25  *** Error:   out  of bounds  for  vehicle
type (1 to 8)

     This  message  is printed  if the  vehicle  type in the emission
rate modification section  is not equal to  1,  2, 3, 4,  5,  6, 7, or
8.   The eight  vehicle  types  in MOBILE4  and their  corresponding
codes are:

l = light-duty gasoline-fueled vehicles  (LDGV)
2 = light-duty gasoline-fueled  trucks I  (0-6000 Ib GVW) (LDGTl)
3  =  light-duty  gasoline-fueled  trucks  II  (6001-8500  Ib  GVW)
(LDGT2)
4 = heavy-duty gasoline-fueled vehicles  (8501+ Ib GVW)  (HDGV)
5 = light-duty diesel-powered vehicles (LDDV)
6 = light-duty diesel-powered trucks  (0-8500  Ib GVW) (LDDT)
7 = heavy-duty diesel-powered vehicles (8501+ Ib GVW)  (HDDV)
8 = motorcycles  (MC)

See Table  2.2-1  and  section  2.2.4.
 07/91

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                               3-15
M 26  *** Error:     out of  bounds  for  pollutant
(1 to 3)

     This message  is  printed  if the  code  for  pollutant on  the
emission rate modification  input  section is not equal to 1,  2, or
3.    MOBILE4   calculates   emission   factors    only  for   1
hydrocarbons,   2  =  for  carbon  monoxide,  and  3  =  oxides  of
nitrogen.  See Table 2.2-1 and section 2.2.4.


M 27  *** Error:     out  of  bounds  for
year (1941 to 2020)

     This message  is  printed  if the  code  corresponding to  the
first  or last model  year to  have  altered emission  rates  is  not
between  41 and  99  or 00 and 20  (corresponding  to  years 1941-1999
and 2000-2020).   See Table 2.2-1 and section 2.2.4.


M 28 *** Error:   Excess data errors prevent further analysis

     This message  is printed  if  the  accumulated  number  of  data
input  errors  exceeds 50.   The run  is  stopped  at this point.   All
input  data  should be thoroughly checked  and  must  be  corrected
before rerunning MOBILE4.1.


M 29 *** Error:   Last year cannot be less  than first year

     This message  is printed if the first model year  to have its
emission  rates  altered is  less than  (before)  the  last model year
to be  altered.  See Table 2.2-1 and section 2.2.4.
M 30 *** Error:    intercept must be positive

     This message  is  printed if a new zero-mile emission level is
_< 0.  See Table 2.2-1 and section 2.2.4.


M 31 Warning:   negative slope for ageing vehicle

     This  message  is  printed  if  the  value  for  the  exhaust
deterioration  rate is  negative.   A  negative deterioration rate
implies    improving    emissions    with    increasing    mileage
accumulation.  See Table 2.2-2 and  section 2.2.4.
07/91

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                               3-16
M 32 *** Error:    out of bounds for year (1960 to
2020)

     This message is  printed  if the  code indicating the  year in
which an I/M program  is  to begin does not fall between 60 and 99,
or  00  and  20  (years 1960  to  2020).    See  Section  2.2.3,  I/M
program description, field 1.


M 33 *** Error:     out  of bounds  for  stringency
(10 to 50)

     This message is  printed  if the stringency of the I/M program
for 1980 and earlier LDVs or 1984 and earlier LDTs  is  not between
10  and  50  (percent).   See Table  2.2-2  and  sections  2.2.5  and
2A.1.3.


M 34  *** Error:    out  of bounds for  I/M Program
compliance rate (0  to 100%)

     This  message   is  printed  if   the  specified   value  for
compliance  rate  of  an   I/M  program  is  not  between  0  and  100
(percent)  inclusive.   See Table  2.2-2  and  sections   2.2.5  and
2A.1.7.


M 35 *** Error:    out  of  bounds for MODYR1 (1941
to 2020)

     This message  is  printed  if  the code  representing the first
model year under  an I/M program is not  between 41  and  99,  or 00
and 20  (years  1941  and 2020).   These years are the limits set by
MOBILE4.  See Table 2.2-2  and sections 2.2.5 and 2A.1.4.


M 36  *** Error:    out  of bounds for MODYR2 (1941
to 2020)

     This message  is  printed  if the  code representing  the  last
model  year  under an  I/M program is not  between 41 and 99, or 00
and  20  (years  1941-1999  or  2000-2020).   See  Table   2.2-2  and
sections 2.2.5 and  2A.1.4.


M 37 *** Error:  MODYR1 cannot  be greater  than  MODYR2

     This message  is  printed  if the first model  year  in  an I/M
program  is  greater than the  last  model year  in an I/M program.
See Table 2.2-2 and sections 2.2.5, 2A.1.4, and 2A.1.5.
 07/91

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                               3-17
M 38  *** Error:   out  of  bounds for  year  (1960 to
2020)

     This message is printed if the calendar year  to be evaluated
is not  between 1960 and  2020  (60 to  99  or 00 to 20)  inclusive.
These  are  the  only  years for  which  MOBILE4  evaluates  emission
factors.  See Table 2.3-1 and section 2.3.2.


M 39 *** Error:   speed must be positive

     This message is  printed if the  value for average  speed (if
SPDFLG =1)  or  any of  the  eight values  of  average  speed  (if
SPDFLG =2) is i 0.0.  See section 2.3.3.


M  40 ***  Error:     valid  ambient  temperature is
0-110 deg (F)

     This message  is printed  if  the specified value  for ambient
temperature  value is  not between 0°  and  110°F  (-23°  and 43°C).
These  are  the  limits  for  application of  temperature  correction
factors.  See section 2.3.4.
M 41  ***  Error:   out  of  bounds for  PCCN  (0.  to
100.)

     This message  is  printed if the input value for percentage of
miles traveled  by non-catalyst  vehicles  in  cold-start  mode is not
between 0 and 100 (percent).  See section 2.3.5.


M 42  ***  Error:   out  of  bounds for  PCCN  (0.  to
100.)

     This message  is  printed if the input value for percentage of
miles traveled  by catalyst-equipped  vehicles  in hot-start mode is
not in between  0 and  100  (percent).  See section 2.3.5.


M 43  ***  Error:   out  of  bounds for  PCCC  (0.  to
100.)

     This message  is  printed if the input value for percentage of
miles  traveled  by catalyst-equipped  vehicles  in  cold-start mode
is not between  0 and  100  (percent).  See section 2.3.5.
 07/91

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                               3-18
M 44 *** Error:   out of bounds for AC (0.  to 1.)

     This  message  is  printed  if  the  specified  value  of  the
fraction   of    air-conditioner-equipped    vehicles   using   air
conditioning   is  not   between  0.   and   l.   inclusive.    See
section 2.3.8.3.


M 45 *** Error:   out of  bounds  for  extra load
(0. to 1.)

     This  message  is  printed  if  the  specified  value  for  the
fraction of vehicles assumed to be carrying an  extra 500  Ib load
is not between 0. and 1.  inclusive.  See section 2.3.8.4.


M 46  ***  Error:    out  of  bounds  for trailers
(0. to 1.)

     This  message  is   printed  if  the  specified  fraction  of
vehicles assumed to be  towing a trailer is  not  between 0.  and 1.
inclusive.  See  section 2.3.8.5.


M  47  *** Error:     out  of bounds  for humidity
(20.  to 140.)

     This message is  printed if  the  specified value  for absolute
humidity  is  not  between  20   and  140  inclusive.   See  section
2.3.8.6.
M 48 *** Error:  There are no sales for vehicle 

     MOBILE4.1  assumes that  no  significant number  of  LDDVs exist
before  1975.   Similarily,  no   significant  number  of  LDDTs  are
assumed to  exist  prior  to 1978.   This  message is  printed  if the
user  inputs  a  positive  VMT   fraction  for  LDDVs  or  LDDTs  for
calendar  years  in  which   they  are  assumed  to  be  virtually
nonexistent.


M  49 ***  Warning:     MYR  sum  not  =  1.  (will
normalize)

     This message  is printed if the  sum of registration fractions
by  model  year  for a given vehicle  type  do not sum to  l.   If the
model year  age registration fractions do  not sum to 1, MOBILE4.1
normalizes  the  fractions  so  that they do.  See Section  2.2.3.
 07/91

-------
                               3-19
M  50  *** Error:     out  of bounds  for  tampering
rate intercept (up to 1.0)

     The  zero-mileage  level of  tampering  cannot  exceed  100%  of
the fleet (1.0  as  a fraction)  for  any combination  of  tampering
type and vehicle type.   See section 2.2.1.


M  51  *** Error:  equation   causes  more  than 12
allowed for any 1 reg/veh/pol

     This message is printed if the  user  attempts to  enter more
than  12  modified  basic  emission  rate equations  for  any single
combination   of   region,   vehicle  type,    or   pollutant.    See
section 2.2.4.


M  52 Warning:   speed  increased to 2.5 mph minimum

     This message is printed if the  average  speed  (if SPDFLG = l)
or  one or  more of the  eight  average  speeds  (if  SPDFLG  =  2)  is
less  than 2.5 mph.  MOBILE4  increases the  value  to 2.5  mph and
continues execution.  See section  2.3.3.


M  53 Comment:  All flags must be corrected before rerunning

     This  message  is  printed  if  one or  more errors  occur  in
reading  the  Control  section flags.  It should appear after a list
indicating  which  flags  are  in error (see  M   1).   The  run  is
aborted  at  this point.   All   flags  in  error  must  be corrected
before the program will continue.


M  54  *** Error:   End-of-file  return  on  read of unit IOUIMD (new
FTP I/M  credits).  Run aborted.

M  55 ***  Error:  Error return on read  of unit  IOUIMD (new FTP  I/M
credits).  Run aborted.

     These  messages are  printed  if the user  specifies alternate
I/M  credits  are to  be  read   in  from  logical  I/O device unit
IOUIMD,  and the user either fails to supply the alternate  credit
data  (M54)   or  the alternate  credit  data  contain  errors  (M55).
Either  of  these errors  must  be  corrected before  attempting to
rerun  the program.
 07/91

-------
                               3-20
M 56  Comment:   A/C correction  factor  will  be  calculated.   Value
of inputted AC usage parameter is ignored.

     This message is printed  if  ALHFLG = 3  and a  non-zero  value
for air conditioning usage  fraction  is entered.  With ALHFLG = 3,
the air  conditioning  usage fraction  is  calculated as  a  function
of the  input dry  bulb and wet  bulb temperatures.   See  sections
2.3.8.3 and 2.3.8.7.


M 57 *** Error:   WB temp cannot be greater  than DB temp

     This message is printed  if  the  input  wet bulb temperature is
greater  than the   input  dry  bulb  temperature.   The  wet  bulb
temperature  is   always less  than or  equal to  the corresponding
dry bulb temperature.   See section 2.3.8.7.


M 58  Warning:   Average miles/day  is zero  for  vehicle class 
and model year 

     This message is printed if BLOCK DATA Subprogram 14  has been
incorrectly modified by the user.


M  59  Warning:    equation     zeroes  all   idle
coefficients  (and   total)   for  IR =  ,  IV =  ,  IP = 

     This  message   is  printed  when  the  user  modifies the  basic
emission  rate  equations  for  the specified region,  vehicle type,
and   pollutant.     All   alternative   emission  equations   cause
MOBILE4.1  to zero  all idle  emission  equations  corresponding  to
the  region,  vehicle  type,  and  pollutant  modified.   See section
2.2.4.


M 60  *** Error:    exceeds  ub  of  highest  myg  in


     This  message  is printed to  indicate that  a default  exit has
been  taken  from  an index  function.   This message  is  generated by
an internal  software  error  check, and should not occur unless the
program code has been damaged.   The run is halted at this point.
The program must be corrected and recompiled before another run.
 07/91

-------
                               3-21
M 61 *** Error:   default used for   in  index  function 

     This message  is  printed to indicate that a default  exit has
been taken from  an  index function.   This message is  generated by
an  internal software  error  check,  and should not occur unless the
program  code  has  been  damaged.   The  run   is  aborted  at  this
point.   The  program  must  be   corrected  and  recompiled  before
another run.


M  62  ***  Error:     out  of  bounds  for  new e.f.
region (1  or 2 only)

     This message  is  printed if  the region  to  which  a  modified
basic  emission  rate applies is  specified to  be  other than 1 (low
altitude) or  2  (high  altitude).   This specification  of  region is
independent of  the region  specified in the  Scenario descriptive
record (see section 2.3.1).  See Table 2.2-1 and section 2.2.4.


M63 ***  Error:     out of bounds
(0. 1 PCHC + PCCC i 100.)

     This  message  is  printed if  the sum of the  cold-start and
hot-start  VMT percentages  for  catalyst-equipped vehicles  is not
between 0 and 100 percent inclusive.  See section 2.3.5.


M  64  ***  Error:     out of bounds
(0. < PCHC + PCCC - PCCN i  100.)

     This  message  is  printed if  the sum of the  cold-start and
hot-start VMT percentages  for catalyst-equipped vehicles less the
cold-start  VMT   percentage  for  non-catalyst  vehicles  is  not
between 0 and 100 percent inclusive.  See section 2.3.5.


M  65 *** Error:  MYR  of  LDDV not equal to LDGV for JDX = 

M  66 *** Error:  MYR  of  LDDT not equal to LDGT1 for JDX = 

     One of both of these messages  is printed  if  the user enters
a  different  registration distribution  by age for  LDGVs  than for
LDDVs  (M65) or for  LDGTls  than  for LDDTs (M66).,  The registration
distribution  by  age  for the  total LDV  (or  LDT)  fleet  is  to be
input  twice  for  the  gasoline-fueled  and   diesel   vehicles  (or
trucks).   MOBILE4.1   apportions  total  registrations  into  the
separate gasoline-fueled and diesel groups based  on diesel  sales
fractions by model  year.  See section  2.2.3.4.
 07/91

-------
                               3-22
M 67  ***  Error:   EFFTP  =  0.  and GSF  = 0.  for vehicle  

     This message will be  printed  if  the named vehicle type has a
positive basic  emission rate  and a  zero  fleet  sales  fraction.
See section 2.2.3.


M 68 *** Error:  EFFTP  <_ 0.  AND VMTMIX > 0.  for  vehicle 

     This message  will  be printed if  no exhaust  emission rates
exist for the named  vehicle  type,  but vehicles of  that  type have
accumulated a nonzero fraction of the total vehicle fleet mileage.


M 69 *** Error:   EFIDLE < 0.  for vehicle 

     This message  is printed  if  the  named  vehicle  type  has  a
positive  idle  emission  factor  and a  zero fleet  sales  fraction.
See section 2.2.3.


M 7Q  ***  Error:  EFIOLE <  0. AND VMTMIX > 0.  for vehicle  out  of bounds  for short test
type  flag (1 to 3)

     This message  is  printed if the value of  ILDT(I)  is not 1 or
2 in the I/M program descriptive record.  See Table 2.2-2.
07/91

-------
                               3-23
M 73  ***  Error:   out  of  bounds for  short  test
type flag (1 to 3)

     This  message is  printed  if  the  value of  ITEST  (Tech  IV+
short test type) is not 1, 2 or 3.   See Table 2.2-2.


M 74  ***  Error:    out of  bounds for  I/M  data
flag (1 to 2)

     This message is printed if the value of the  NUDATA flag  (the
flag  from the  I/M  program descriptive  record  indicating whether
or not new  I/M  credits  are to be read from unit  IOUIMD)  is not 1
or 2.   See Table 2.2-2.


M   75  ***   Error:    < value   of   LAPSY>   out   of   bounds   for
anti-tampering program start year

     This  message is printed  if  the value of  the  start year for
the selected anti-tampering  program (ATP)   is  not  in  the  range
1960 to 2020  (60-99, 00-20).  See Table 2.2-3 and section 2A.1.2.


M   76  ***  Error:       out   of   bounds   for
anti-tampering program 1st model year

     This  message is printed  if the value of the first model year
included  in the  selected  ATP is not  in the  range  1941  to  2020
(41-99, 00-20).   See Table 2.2-3 and section 2A.1.4.


M   77  ***   Error:    < value   of  LAPLST>   out   of   bounds   for
anti-tampering program  last model year

     This  message is printed  if the value of the first model year
included  in the  selected  ATP is not  in the  range  1941  to  2020
(41-99, 00-20).   See Table 2.2-3 and section 2A.1.5.


M  78   ***  Error:     out  of   bounds  for
anti-tampering  vehicle  type (1  to 2)

     This  message is  printed  if  the value  entered  for  the ATP
vehicle  class  inclusion  flag  for  vehicle  type  I   is  not either
1 (not covered) or 2  (covered).  See Table 2.2-3.
07/91

-------
                               3-24
M  79 ***  Error:   < value  of  EVP>  out  of  bounds  for  evap  ATP
effectiveness rate (0. to 1.)

     This  message is  printed  if  the  value  calculated for  the
evaporative ATP  effectiveness  rate  in  the ATP  effectiveness  rate
matrices generated  by MOBILE4  is not  in the  range 0.0 to  1.0.
These  rates  act  as  percentage  credits,  and   hence   must  be
nonnegative and not exceed unity.


M  80 ***  Error:   < value  of  RATE> out  of  bounds  for exh  ATP
effectiveness rate (0. to 1.)

     This  message is  printed  if  the  value  calculated for  the
exhaust  ATP effectiveness  rate  in the  ATP  effectiveness  rate
matrices generated  by MOBILE4  is not  in the  range 0.0 to  1.0.
These  rates  act  as  percentage  credits,  and   hence   must  be
nonnegative and not exceed unity.


M  81  ***  Error:    out  of  bounda  for exh  ATP
effectiveness rate (0. to 1.)

     This  message is  printed  if  any  column  of  each  of the 4
exhaust  ATP effectiveness  rate matrices  generated by MOBILE4  on
the  basis   range 0.0  to  1.0.   These  rates  act  as  percentage
credits, and hence must be nonnegative and not exceed unity.


M  82 *** Error:   out of bounds for type  of  I/M
inspection  [1  (centralized)  or 2  (computerized  decentralized)  or
3  (manual decentralized)]

     This message is  printed if the value of the  I/M program type
specified  in the I/M descriptive  record is  not  1, 2, or  3.   The
run  is  aborted  at  this  point.    See  Table  2.2-2  and sections
2.2.5, 2A.1.12,  2A.1.13, and 2A.1.14.


M  83 Comment:    One or more  evaporative temperatures (input daily
maximum,  input  ambient,  calculated hot  soak, and/or   calculated
running  loss)  is 40F  or  less, or  the  input daily minimum is 25F
or   less;  no  evaporative  emission  factors   (hot  soak,  diurnal,
running  loss, or  resting loss) will be calculated

     This  message  is printed  if  (1)  one  or more temperatures
calculated  by MOBILE4.1 for  correction  of  emissions (TEMFLG =  1),
or  (2)  the input ambient  temperature   (TEMFLG  =  2), is  less than
or   equal   to   40°F  (4°C);   or   (3)   the   input  daily  minimum
 07/91

-------
                               3-25


temperature is  less  than or  equal  to 25°F  (-4°C).   See sections
2.1.13  and   2.2.11.5   for   additional   information.    Crankcase
emissions will still be  calculated,  resulting in a small non-zero
evaporative emission factor representing crankcase emissions only.


M  84  *** Error:     out  of bounds  for  onboard
VRS vehicle class flag (1 to 2)

     This message  is  printed  if  the value of the IVOB flag  for
vehicle type  IV,  indicating  whether or  not  the vehicle  type  is
subject to  the  requirements  of  an onboard VRS  system,  is not  1
or 2.   See Table 2.2-4 and section 2.2.7.


M 85       Message slot 85 is not assigned in MOBILE4.1


M  86  ***  Error:    out of bounds for no. of stage
II phase-in years (1 to 5)

     This  message is  printed  if  the  value of NPHASE   in  the
Stage II  VRS  descriptive  record  is not  between  1  and  5.   See
Table 2.2-4 and section 2.2.7.


M  87  *** Error:     out  of
bounds for VRS or RVP controls start year

     This message  is  printed  if  any of  the  specified  start years
for Stage II  VRS, onboard VRS, or  "period  2" volatility (RVP)  is
not between 1989  and  2020 (89-99 and 00-20).  See sections 2.2.7
and 2.2.13.
M  88  *** Error:    out of bounds  for  diesel  sales fraction
(0. to 1.)

      This  message  is printed  if  the user  has  supplied  diesel
sales  fractions  by model year for LDVs  and  LDTs,  and one or more
of  the  fractions  is not between  zero and one.   This  message is
new in MOBILE4.1.  See section 2.3.10.


M  89  *** Error:   out of bounds for  flag PROMPT

      This  message is  printed if PROMPT  does not equal  1,  2, 3,
or 4.   The  run  is  stopped,  and this  correction  must be  made
before the program will  proceed.  See  section 2.1.1.
 07/91

-------
                               3-26
M 90 Warning:   RVP is reset to 

     This  message  is   printed  if  the  input  value  for  either
"period 1"  or  "period  2"  RVP,  or  the value  of either  of  these
after fuel weathering is accounted for, is outside  the  RVP limits
of 7.0 to  15.2  psi  inclusive;  or, if the value  of  RVP  to be used
in   the   diurnal   or   hot  soak  evaporative   emission  factor
calculation  exceeds  an  upper limit  for  each that  depends on the
temperature to be used  in  that  calculation.   See Table  2.2-5 and
sections  2.2.12  and 2.2.13.   The value printed  first  is reset by
MOBILE4.1  to     before  the  emission   factors  are
calculated.


M  91  ***  Error:     out  of  bounds for  minimum
daily temperature

M  91  ***  Error:     out of  bounds for maximum
daily temperature

     One of these messages is printed  if  either  the input minimum
or  maximum  daily  temperature   is  outside  the  limits  set  by
MOBILE4.1  (0  _<  minimum  <^  100,  10  £  maximum   <_  120).   See
Table 2.2-5 and section 2.2.11.


M  92  ***  Error:   Max daily temp  =   <  min daily
temp

     This  message  is printed if  the  minimum daily temperature is
greater than the maximum daily temperature.  See  section  2.2.11.


M  93  *** Error:   out of  bounds for % TLVMT  (0.  to 1.)

     This message is  printed if the user is supplying trip  length
distribution data to be used in  calculating  running loss  emission
factors,  and one or more  of the values  is  not  between zero and
one.  This message is new in MOBILE4.1.  See section 2.3.11.


M  94 *** Error:   % TLVMT  sum not = 100.  (will normalize)

     This message is  printed is the user is supplying trip  length
distribution data to be used in  calculating  running loss  emission
factors,  and  the  sum  of  the  six values  is not  100   (percent).
This message is new in MOBILE4.1.  See section 2.3.11.
 07/91

-------
                               3-27
M 95 ***  Error:   Ambient  temperature =  is < daily
min temp or < daily max temp

     This  message  is  printed  if  the ambient  temperature  (see
section 2.3.4)  is either less  than the minimum daily temperature
or  greater  than  the  maximum  daily  temperature  (see  section
2.2.11).


M 96 Warning:  speed  reduced to 65 mph maximum

     This message is printed if the  average  speed  (SPDFLG = l) or
one or  more of  the eight average  speeds  (SPDFLG  =  2) is greater
than 65 mph.  MOBILE4.1 reduces the  value  to 65 mph  and continues
execution.   This is revised from MOBILE4,  when the  maximum speed
was 55 mph.  See section 2.3.3.


M  97  ***  Error:   < Value  of  A>  out of  bounds  for Wade  Index
calculation  (CALUDI) of A, pass :  must be >_ 0.0.

     This  message  is  printed  if   an  unrealistic combination of
very high fuel volatility  (RVP)  and  temperature  values  are used
in the calculation  of  diurnal evaporative emissions.  The  run is
aborted  at  this  point.   Re-check  all input RVP  and temperature
values.   See sections 2.2.11 -  2.2.13.


M  98  Warning:   Diurnal  temperature  rise  (max  temp  - min  temp  =
)  is > 40F; diurnal  evaporative emission  factors will be
calculated,  but  may be  inaccurate.

     This  message  is  printed if the  difference  in the input daily
minimum and  maximum temperatures  is greater than 40°F (4°C).  See
section 2.2.11.5.


M  99  *** Error:     out   of  bounds   for  Stage II
efficiency  for  LDGV (0 to 100%) or  out  of bounds
for Stage II efficiency for  HDGV  (0 to 100%)

     This message  is  printed  if  the  specified value  for  the
efficiency of  Stage  II  VRS  at  controlling refueling  emissions
from  LDGVs and  LDGTs,  or from HDGVs,  is  not  between  0  and 100
percent.   See Table 2.2-4 and  section 2.2.7.
 07/91

-------
                               3-28
M 100 *** Error:    out  of  bounds
for I/M Program waiver rate 00 to 50%)

     This message  is  printed if  the values specified for  either
waiver  rate for  I/M  programs   on  the  I/M  program  descriptive
record  is   not  between  0  and  50 percent  inclusive.    See  Table
2.2-2 and sections 2.2.5 and 2A.1.6.


M 101 *** Error:    out of bounds for frequency of
I/M inspection  [1 (annual) or 2 (biennial)]

     This message  is  printed if  the  value of  IFREQ specified on
the  I/M program  descriptive record is not  l  or  2.    See  Table
2.2-2 and sections 2.2.5 and 2A.1.8.


M  102  Warning:   High  altitude   I/M  scenario  requires user  to
supply high altitude values for Tech 1&2 I/M credits arrays

     This message  is  printed if the  user  specifies high-altitude
as the  region  for  which emission factors are to be calculated and
also  specifies  that  an  I/M  program  is  to be assumed.   The I/M
credits  contained in  the  MOBILE4  code  are  applicable only to
low-altitude  regions.   The  MOBILE4.1 tape  and diskette  include
standard high-altitude region I/M credit  matrices,  which must be
read  in on  logical I/O unit 3.


M 103 ***  Error:    out of  bounds  for  type of ATP
program [1  (centralized) or 2 (decentralized)]

     This message  is  printed if  the  value of the  ATPPGM  flag on
the  ATP descriptive   record,  indicating  the  type  of ATP  to be
modeled, is not 1  or 2.  See Table  2.2-3 and  sections  2.2.6 and
2A.1.8.


M 104 *** Error:  out  of  bounds for frequency of
ATP  inspection  [1  (annual) or 2  (biennial)]

      This message  is  printed  if the value of the ATPFQT flag on
the   ATP   descriptive   record,   indicating   the   freguency  of
inspection  in the ATP  to be modeled,  is  not  1  or 2.  See  Table
2.2-3 and sections 2.2.6  and 2A.1.8.
 07/91

-------
                               3-29
M  105  ***  Error:   < Value  of  CRATP>   out  of  bounds  for  ATP
compliance rate, must be in the range 0.% to 100.%,  inclusive

     This message is printed if the  specified ATP  compliance rate
is not  between  0 and 100 percent inclusive.  See Table  2.2-3 and
sections 2.2.6 and 2A.1.7.


M  106  ***  Error:     out of  bounds for ATP
disablement inspections [1  (no) or 2 (yes)]

     This message  is printed  if  the value  of  any  of  the  eight
DISTYP  flags  on the ATP decriptive  record,  indicating whether or
not each of eight  possible inspections is performed,  is not 1 or
2.
See Table 2.2-3 and sections 2.2.6 and 2A.2.3 through 2A.2.10.


M  107  ***  Error:   Error  reading  ATP program description  in the
ONE-TIME data section

     This message  is printed if there is  an error  in reading the
ATP descriptive  record.  The run is aborted at this point.   Check
the formats and all input values closely.  See Table 2.2-3.


M  108  Warning;   The  ATP compliance  rate  of   is
not equal to the  I/M compliance rate of 

     This message  is printed  if  the  specified ATP compliance  rate
is not  equal  to  the specified I/M  compliance  rate.   The program
will  continue execution,  but since  such programs  are  generally
run   in  conjunction  in  a  given  area,  the  compliance   rates
generally should be equal for both programs.  See sections 2.2.5.


M  109   Warning:   The  ATP  inspection  frequency   is   and the  I/M  inspection  frequency  is 

     This  message is printed  if  the ATP  inspection  frequency  is
not equal  to  the specified I/M inspection frequency.  The program
will  continue execution,  but  since  such programs  are generally
run  in  conjunction  in  a given area,  the frequency of  inspection
generally  should  be  the same  for both  programs.    See sections
2.2.5,  2.2.6, and  2A.1.8.
 07/91

-------
                               3-30
M 110   Warning:   The ATP  inspection  type  is  ,
the I/M inspection type is 

     This message  is printed  if the  specified ATP  program type
(i.e.,  centralized or  decentralized)   is  not  the   same  as  the
specified I/M program type.  The program will continue execution,
but  since  such  programs  are  generally  run  in conjunction  in  a
given  area,  the program  type generally should be  the  same for
both programs.  See sections 2.2.5,  2.2.6, 2A.1.12, and 2A.1.13.


M 111  *** Error:     is  < min
daily  temp or > max daily temp

     This  message  is   printed  if  TEMFLG  =  1  and one of the
temperatures  calculated for correction  of  exhaust,  evaporative,
running  loss,  or resting  loss  emissions is  outside  of the  range
of  the specified minimum  and  maximum  daily  temperatures.    Since
these  calculations  use  the  input  minimum  and  maximum   daily
temperatures to  start with,  this is an  internal error  check.  If
this   message  appears,   and   the   minimum  and   maximum   daily
temperatures   are   correct  and  meet   all   of   the   necessary
conditions,  damage has  occurred to either  the  source code or the
compiled program.  Recompile and attempt the run again.


M  112  Warning:   Purge/pressure entry  (HCFLAG =  5)  is  for EPA
 in-house use  only.   There is no user application  of  this feature
which  would be acceptable for submission to EPA

M  113   Warning:   MPD/TPD  entry  (HCFLAG =  6)  is  for EPA  in-house
use  only.   There  is no  user  application  of  this  feature   which
would  be acceptable for submission  to EPA

M 114  Warning:  IPRGYR must be  >_ IM24YR  in  IM240 program

M   115   Warning:    The   alternate  I/M  credits  necessary  for
determining  the benefit of  the IM240 test have  not been provided

M  116  Warning:   The   I/M  stringency  input  must  be  adjusted to
account  for  the benefit  of the  IM240  test for model years  prior
to  1981

     Messages  112  through  116   are  generated by   inappropriate
 input  data  being  used  in conjunction with features of MOBILE4.1
 intended  for  use  by  EPA  only.   These  features  are  not   fully
 implemented   and   users   should  not  attempt   to  model   emission
 factors using these features.
 07/91

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                               3-31
M 117 ***  Error:     out of bounds for by model  year  table pick
(1 to 2)

     This  message  is  printed if  the  values of the  two flags  at
the  end of  the  by model  year  inclusion vector  are  not 1  or  2.
See section 2.2.16.
M 118  ***  Error:   Input of diesel sales  fractions  not  allowed  in
One-Time Data section

     This message  is  printed  if the user sets  DSFLAG  = 2  on  the
LAP  record and  also  sets  LOCFLG =  2.   See sections  2.2.15  and
2.3.10.


M  119 Warning:   Zero  tampering  is  for EPA   in-house use only.
There  is  no  user  application  of  this feature   that  would  be
acceptable for submission to EPA

     This  message  is  generated  in  conjunction  with use of  a
feature  of MOBILE4.1  intended for use by EPA only.  Users  should
not attempt to model emission factors using this feature.


M  120 Warning:   MOBILE4.1  does  not  model  most  1993 and later
Clean  Air Act  requirements;  emission   factors for CY 1993  and
later  are affected

     This  message  is  printed  whenever  MOBILE4.1  is  used  to
calculate emission factors  for calendar years 1993  or later.


M  121  ***  Error:    ATP  program  including  evaporative   control
system inspection MUST  also include gas cap  inspection

     This  message  is  printed if an ATP is specified that includes
evaporative  emission   control   system  inspection  but  does  not
include  gas cap inspection.   See  section  2.2.6.4 and Table  2.2-3.
07/91

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                               3-32
3.3  FORMATTED REPORT OUTPUT

     There are  five  different types  of  formatted report  output.
The user  specifies  which of  the  five is to be  generated through
assignment of a value  to the OUTFMT  flag  in the  Control  section
(section  2.1.15).    If  OUTFMT =  l  or 2,  MOBILE4.1 generates  a
formatted  data  set  suitable  for  use  as  an  input  file  for
subsequent computer  analysis ("numeric" output).   If OUTFMT  =  3
or 4, a  report  more suitable  for  visual inspection  and analysis
("descriptive"  format)   is  generated.  These  latter outputs  are
designed  to  provide  a  well-annotated  record  of   the  user's
analysis.  If OUTFMT =  5,  the  output produced  by OUTFMT =  3 is
produced,  along  with   additional  tables  providing  detailed  by
model year emission factor information.

     3.3.1  221-Column Numeric Format (OUTFMT = 1)

     If  OUTFMT   =   1,   the  longest  numeric  format  report  is
generated.   It  consists  of  four heading  records, which provide
minimal  column  descriptions,  followed by one  to  ten  records per
scenario  evaluated.   The number  of  records  produced  for  each
scenario  is   determined  by  the  values  assigned  to  the  PRTFLG,
IDLFLG, and HCFLAG flags  in the Control section  (see section 2.1).

     Each  record  of this output  format  consists  of 35  subject
columns.   (In the description that  follows, the term "column" is
used to  refer to  the subject columns, while the term "character"
is  used  to refer to the number of  individual,  one-space columns
spanned  by   the   subject  column.)    Example   1   in   Chapter  5
illustrates  this  output  format.    The  subject  columns  and the
value(s) shown in each are described below:

     One  other  item to  note  with respect  to  the  numeric output
formatted  report  options  is  the  "carriage  control"  characters
used to control the  placement of  records.   FORTRAN incorporates a
character  in column 1  of each  output  record  which is  used to
indicate   carriage   control   (such   as   "start   new   page,"
"double-space   before   printing   next   record,"   and   similar
instructions).   If  OUTFMT =  l  or 2  and  the formatted  report is
directed  to   a  line file,  the  first character  space  is  reserved
for  this carriage control  character.   Thus,  all of  the columns
that follow  in  each record are shifted one character space to the
right:

     Format       Content
         IX      (carriage control character)
         II      (Column  1:  Region)
      IX,12      (Column  2:  CY of evaluation), etc.
 07/91

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                               3-33


The total record  length  is  then 221 columns  (OUTFMT  = 1)  or  140
columns (OUTFMT = 2).

     If  the numeric  output  formatted report  is  directed to  a
printer,  such  as  was done  in  generating Examples  1  and 2  in
section  5.1.1,  the instructions provided  by  the  carriage control
characters  are  executed,  but the  characters  are not  printed  and
no space  is  reserved for  them on the hard copy.  Thus, the format
of the printed version of  OUTFMT = 1 or 2  reports  does  not begin
with  IX  (carriage  control  character),  and  the  total  length  of
each record  is  220  columns  (OUTFMT = 1) or 139 columns  (OUTFMT =
2).

     Column  1:  Region.  The column is one character wide  (format
II).   The  column heading  is  "Reg"   (printed  vertically).   The
value  shown  is  either  1   (low-altitude)  or  2  (high-altitude).
This  column  contains  values  on  all  exhaust  emission  factor
records,  but  is  blank  for  the  component  HC  emission  factor
records.

     Column  2:  Calendar year of  evaluation.  The column is three
characters  wide  (format  IX, 12).   The column heading  is "CY."
The  value shown  is  the  last 2  digits of the calendar  year  of
evaluation.  Note that  CY 2000-2009 will  appear  as 0,  1,  ...,  9,
not  00,  01,  ...,  09.  This  column  contains values  on all  exhaust
emission  factor  records,   but  is  blank  for  the  component  HC
emission  factor records.  See section 2.3.2.

     Columns 3-10:   Vehicle Speeds.  The column  is 40 characters
wide  (format 8F5.1).   The  column  heading is  "Vehicle   Speeds."
The  values  shown are the  average speeds  used for  each  of  the
eight vehicle  classes,  in  this order:  LDGV,   LDGTl, LDGT2, HDGV,
LDDV, LDDT,  HDDV, MC.  If  SPDFLG = 1,  all eight  speeds  have the
same  value.   In  print,  the values are  separated by slashes (/).
For  example,  if  SPDFLG  =  1 and  speed  =  19.6  mph,  this  line
appears:

             19.6/19.6/19.6/19.6/19.6/19.6/19.6/19.6

This  column contains  values   on  all  exhaust  emission  factor
records,  but  is  blank  for  the  component  HC  emission  factor
records.

     Column   11:    Ambient   Temperature.   The  column  is  four
characters  wide  (format IX,  13).   The column  heading is  "Amb Tern"
on two  lines.   The value(s)  that  appear  in this column  depend on
the   value  of   TEMFLG:    If  TEMFLG   =   1,   the  temperature(s)
calculated  by  MOBILE4  based on  the  input  minimum  and  maximum
daily temperatures  for  the  correction  of  exhaust  HC,  CO,  AND NOx
emission  factors  are  printed  on  the  applicable  line.   If
 07/91

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                               3-34
TEMFLG = 2, the  input ambient temperature  is  echoed back  on  the
exhaust emission  factor  records.   This column  contains  values on
all  exhaust  emission  factor  records,   but  is  blank  for  the
component  HC  emission   factor   records   (exhaust,   evaporative,
refueling, running loss,  and resting loss).

     Columns 12-14:   Operating Mode  Fractions.   The column  is 18
characters wide  (format  3F6.1).   The  column heading is "Cold/Hot
Start."   The values  that appear  are the input  values  for  PCCN,
PCHC,  and PCCC,   in  that order.   This column contains  values on
all  exhaust  emission  factor  records,   but  is  blank  for  the
component HC emission factor records.

     Column  15:    Altitude.   The  column  is  7  characters  wide
(format  F7.0).    The  column  heading  is  "Alt.   in  Ft."  on  two
lines.   This  feature is residual  from  earlier  versions  of  the
model.  The value listed will be either  500 [if  the input region
is  1  (low-  altitude)]   or  5500  [if  the  input  region  is  2
(high-altitude)].   This   column  contains values on all  exhaust
emission  factor  records,  but  is  blank  for  the  component  HC
emission  factor records.

     Column  16:   Pollutant.   The column is two characters wide
(format  IX, Al).   The column  heading  is  "Pol"  printed vertically.
The  values  and their  corresponding identification  of  pollutants
are:
Value     Pollutant   Value

  1       Total HC         X
  2       Exhaust CO       V
  3       Exhaust NOx
  4       Idle HC          R
  5       Idle CO          T
  6       Idle NOx         S
                                      Pollutant

                                         Exhaust HC
                                         Evaporative HC
                                          (includes crankcase)
                                         Refueling HC
                                         Running loss HC
                                         Resting loss HC
     Columns  17-26:   Composite Emission  Factors.   The  next ten
columns  are  each  eight  characters  wide  (format   10F8.3).   The
column  headings  are  "Composite  Emission Factors"  centered over
all  80  characters,  with  the  individual  columns headed  in  order
by:  "LDGV,"  "LDGT2,"  "LDGT,"  "HDGV, "  "LDDV, " "LDDT,"   "HDDV, "
"MC,"  and "All Veh" .   These  represent  the emission  factors for
the  pollutant identified  in  column 16,  for the following  vehicle
classes    in    order:     light-duty   gasoline-fueled   vehicles,
light-duty gasoline-   fueled  trucks   l   (up  to   6000  Ib  GVW) ,
light-duty gasoline-fueled trucks  2 (6001-8500 Ib GVW), all  LDGTs
together   (weighted  results  for   LDGTls  and  LDGT2s),  heavy-duty
gasoline-fueled  vehicles  (over 8500 Ib  GVW),  light-duty  diesel
vehicles,   light-duty  diesel   trucks   (up   to  8500   Ib   GVW),
 07/91

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                               3-35


heavy-duty diesel  vehicles  (over 8500  Ib  GVW),  motorcycles,  and
all vehicles  combined (weighted by the VMT mix; see  below).   The
emission factors are  listed to 3  decimal  places (0.001 g/mi)  in
this type of formatted report.

     Columns  27-34:   VMT Mix.   The next  eight columns are  each
six  characters wide  (format  8F6.3).   The  column  headings  are
"Vehicle Mix"  centered over  all  48 columns,  with  the  individual
columns  headed in  order  by:   "LDGV,"  "LDGT1," "LDGT2,"  "HDGV,"
"LDDV,"  "LDDT,"  "HDDV,"  and "MC."  The  values are  the VMT  mix
input by the user for the current  scenario.  This  column contains
values  on  all exhaust emission  factor  records, but  is  blank for
the component HC emission factor records.

     Column  35:   Scenario  Title.   The  column  is  17  characters
wide  (format  1X,4A4).    The heading  is  "Scenario  Title."   The
value  is the  echo of  the  scenario title input as  part of  the
Local  Area Parameter  record.   See sections  2.2.8 and  2.2.9  and
Table 2.2-5.


     3.3.2  140-Column Numeric Format (OUTFMT = 2)

     If  OUTFMT =2,  a  somewhat shorter numeric  format  report  is
generated.  As  in  the case  of  the longer numeric  format  report,
it  consists  of  four  heading  records  providing   minimal  column
descriptions,  followed  by   one   to   ten   records   per  scenario
evaluated.   The  number of  records  produced for each scenario  is
determined  by  the values  assigned to  the  PRTFLG,   IDLFLG,  and
HCFLAG  flags  in the Control  section.

     Each  record  of  this  output  format  consists  of  25  subject
columns.   (In the  description that follows, the term "column"  is
used  to refer to  the  subject columns,  while  the term "character"
is  used to refer  to  the  number of individual,  one-space columns
spanned  by  the   subject   column.)    Example   2   in  Chapter   5
illustrates  this  output format.   Note that  this   output  will  be
truncated  after  a maximum  of  132  columns  if  printed in landscape
format  on  standard 8.5x11 inch paper unless wrapped  around.   See
the discussion of  carriage control characters provided  in section
3.1.1,  which  is  also  applicable in  this  case.   The  subject
columns and the value(s) shown  in each are described  below:

     Column  1:   Region.   The column is one character wide (format
II).   The  column  heading  is  "Reg"   (printed   vertically).   The
value   shown  is  either  1   (low-altitude)  or  2 (high-altitude).
This   column   contains  values  on  all  exhaust  emission  factor
records,   but  is   blank  for  the  component  HC emission  factor
records.
 07/91

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                               3-36


     Column 2:  Calendar year of evaluation.  The  column  is  three
characters wide  (format  IX,12).  The  column heading is "CY."  The
value  shown  is   the  last  2  digits  of  the  calendar  year  of
evaluation.   Note  that  CY  2000-2009  appear as 0,  1,  ...,  9,  not
00,  01,   ...,  09.   This  column contains  values  on  all  exhaust
emission  factor  records,  but  is blank   for  the  component  HC
emission  factor  records  (exhaust,  evaporative,  refueling,  running
loss, and resting loss).

     Column   3:    Ambient   Temperature.    The  column   is   five
characters wide  (format  IX,13).  The  column heading is  "Amb Tern"
on  two  lines.  The value(s) that appear in this  column depend on
the  value   of   TEMFLG:    If  TEMFLG  =   1,   the  temperature(s)
calculated  by MOBILE4  based  on the  input  minimum  and  maximum
daily temperatures  for  the  correction of exhaust HC,  CO,  and NOx
emission  factors   are   printed on  the  applicable   lines.   If
TEMFLG =  2,  the  input ambient  temperature  is echoed  back  on the
exhaust  emission factor records.   This  column  contains values on
all  exhaust  emission  factor  records,  but  is  blank  for  the
component HC  emission factor records.

     Column  4-6:   Operating Mode  Fractions.  The column  is 18
characters wide  (format  3F6.1).  The column  heading  is "Cold/Hot
Start."   The values  that appear  are  the   input values  for  PCCN,
PCHC, and PCC, in that order.   This column contains values on all
exhaust  emission factor records, but  is blank for the component
HC  emission  factor  records.

     Column  7:   Pollutant.   The  column is  two  characters wide
(format  IX,Al).   The column heading  is "Pol" printed vertically.
The  values  and  their  corresponding identification of  pollutants
are:
       Value     Pollutant          Value    Pollutant

          1       Total HC             X      Exhaust HC
          2       Exhaust CO           V      Evaporative HC
          3       Exhaust NOX                   (includes crankcase)
          4       Idle HC              R      Refueling HC
          5       Idle CO              T      Running loss HC
          6       Idle NOx             S      Resting loss HC


     Columns  8-17:   Composite  Emission  Factors.   The  next  ten
columns   are each  eight  characters  wide  (format 10F8.3).   The
column headings  are "Composite  Emission Factors"  centered over all
80  characters,  with the  individual columns  headed  in  order by:
"LDGV:,  "LDGT1", "LDGT2",  "LDGT",   "HDGV",  "LDDV",  "LDDT",  "HDDV",
"MC",  and "All  Veh."  These represent  the  emission factors  for the
pollutant identified   in   column   7,   for   the  following   vehicle
classes  in  order:   light-duty gasoline-fueled vehicles, light-duty
 07/91

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                               3-37


gasoline-fueled  trucks   1   (up  to   6000   Ib  GVW),   light-duty
gasoline-fueled  trucks  2 (6001-8500  Ib GVW),  all LDGTs  together
(weighted    results    for   LDGTls    and   LDGT2s),    heavy-duty
gasoline-fueled  vehicles  (over 8500  Ib GVW),  light-duty  diesel
vehicles, light-duty diesel trucks (up to 8500  Ib  GVW),  heavy-duty
diesel vehicles  (over  8500 Ib  GVW), motorcycles,  and all  vehicles
combined (weighted by the VMT  mix;  see columns 18-25  below).   The
emission factors  are listed to two  decimal places  (0.01  g/mi)  in
this type of formatted report.

     Columns 18-25:  VMT Mix.   The next eight  columns are  each six
characters wide  (format 8F6.3).  The  column headings are  "Vehicle
Mix"  centered  over  all 48 columns,  with  the individual  columns
"LDGV,"  "LDGT1,"  "LDGT2,"   "HDGV,"   "LDDV,"   "LDDT,"  "HDDV,"  and
"MC."   The  values  are  the VMT  mix  input by  the  user  for  the
current  scenario.    This column contains  values  on all  exhaust
emission  factor  records,  but  is  blank  for  the  component  HC
emission factor records.

     3.3.3   112-Column Descriptive Format (OUTFMT = 3)

     If  OUTFMT  = 3, a  well-annotated  descriptive  format output is
produced.    This  format   is   designated   for   ease   of   visual
inspection,  with more  complete labeling and  heading information.
The  112 column width allows this format to  be  printed in landscape
format (sideways) on standard 8.5x11 paper.

     The exact  content  of the  report  is determined  by a number of
flag settings.    Information  applicable  to the   entire run  (all
scenarios)  is  listed  first,  followed by  a series  of  blocks,  one
per  scenario evaluated.   The  scenario output  blocks  are separated
by solid lines.

     Each  possible  component  of  this  output  format  is  briefly
described  below.  Example  3  in  Chapter  5  is an  illustration of
this type of output.

     The  first  line  of the report  is the project  title  input by
the  user  (section 2.1.1).  This is followed by a  blank line,  then
by the following optional information  if applicable:

      If  the  output units have  not been reassigned (section 2.1.2),
then any diagnostic  messages  generated  will  follow  the  project
title.

      If  an  I/M  program  is  to  be  modeled   (IMFLAG  = 2),  a block
echoing  the descriptive information  on  the  I/M  program will  be
printed.  This block consists of 16 lines.  For example:
 07/91

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                               3-38


     I/M program selected:

     Start year (January 1):                  1981
     Pre-1981 MYR stringency rate:              20%
     First model year covered:                1965
     Last model year covered:                 2020
     Waiver rate (pre-1981);                  10.%
     Waiver rate (1981 and newer):            10.%
     Compliance rate:                        80.%
     Inspection type:                        Centralized
     Inspection frequency:                    Annual
     Vehicle types covered:                   LDGV  - Yes
                                             LDGT1  - Yes
                                             LDGT2  - Yes
                                              HDGV  - No
     1981 & later MYR test type:              Idle

     If  the user  has  supplied  alternate   I/M  credits,  then  a
message  indicating  this   can  be  printed  following this  block.
This message must be provided in the alternate I/M credit  file to
be read from logical I/O unit 4.

     If  the  user has  selected modeling of  the   effects  of  an
anti-tampering program  (ATP),  the  program description  is  echoed.
This block consists of 19 lines.   For example:

     Anti-tampering program selected:

     Start year (January 1):                 1981
     First model year covered:                1970
     Last model year covered:                2020
     Vehicle types covered:                  LDGV
     Type:                                   Centralized
     Frequency:                              Annual
     Compliance Rate:90.0%
     Air pump system disablements:            Yes
     Catalyst removals:Yes
     Fuel inlet restrictor disablements:     Yes
     Tailpipe lead deposit test:              No
     EGR disablements:                       Yes
     Evaporative system disablements:        Yes
     PCV system disablements:                Yes
     Missing gas caps:                       No

     If  both I/M  and anti-tampering  programs are  selected,  the
I/M block precedes the ATP block in the output.

     If  alternate basic emission rates  are modeled  (NEWFLG  =2),
message  M59  (see section  3.2.2)  will  be printed,  followed by a
table summarizing the changes made to the BERs.  For example:
07/91

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                               3-39


                Emission Factor Modification Profile
Equation Reg Veh Pol First MY Last MY    Base    PR    50K PR Altered
    1     212    1980     1986    30.05  3.01      3.44   Yes

     If one  one local area  parameter  record is to be  applied to
all scenarios  (LOCFLG = 2),  this information is  printed on  the
next two  lines.   The first  line  lists the  scenario  name and the
minimum and  maximum  daily temperatures.   The  second  line  lists
the period  1  RVP,  the  period 2  RVP,  and  period 2  start  year.
Each is clearly indicated with a label.

     Finally,  one  of the  following  messages  will   be  printed
before the  individual scenario results.   If NMHFLG  =  l:   "Total
HC emission  factors  include  evaporative HC  emission  factors";  if
NMHFLG =2:  "Non-methane HC  emission  factors  include evaporative
HC emission  factors"; if  NMHFLG  = 3:   "Volatile organic compound
emission  factors  include  evaporative  HC  emission  factors";  if
NMHFLG  =  4:    "Total organic gasses  emission  factors  include
evaporative  HC  emission  factors";  and  if NMHFLG  =  5:  "Non-
methane organic gasses  emission  factors  include   evaporative  HC
emission factors".

     The  above information  is followed  by  a series of scenario
output blocks,  separated for each scenario by solid  lines.   Each
of these blocks has the  same format and structure.

     After  the  line  indicating  the  start  of  a  scenario output
block, the following  one-line messages are  printed if  applicable
to that scenario:

     If TAMFLG =2:

           "User supplied  tampering and misfueling rates"

     If MYMRFG = 2:

           "User supplied  mileage  accrual distributions"

     If MYMRFG =3:

           "User supplied  vehicle  registration distributions"

     If MYMRFG =4:

           "User supplied  mileage  accrual distributions, vehicle
             registration distributions"

     These  messages  are  followed by  two  lines   describing   the
scenario  being  modeled.  The first  line  includes  the  calendar
year of evaluation, whether  or not  an  I/M program  is  modeled,  the
07/91

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                               3-40


ambient  temperatures  used to  correct  exhaust  HC,  CO,  and  NOx
emissions,  and the  region (low-  or high-altitude).   The second
line  includes whether  or not  an ATP  is modeled,  the operating
mode  fractions,  and  the  altitude  (500  ft  for   low-altitude  and
5500  ft  for  high-altitude).   Each  of  these  is  clearly  labeled.
The three ambient temperatures apply in order to HC, CO, and NOx.

     Two  additional  lines containing  the  local   area  parameter
record  information  follow,  if  LOCFLG  =  1  (separate  local  area
parameter record  for each  scenario).   The  first   line  lists  the
scenario  name and  the  minimum  and  maximum  daily temperatures.
The second line lists the period 1 RVP, the  period  2  RVP,  and the
period 2 start year.  Each is clearly indicated by  a label.

     The next  line starts with  "Veh. Type:" and continues across
with  ten column  headings.   In  order,  these   are LDGV,  LDGT1,
LDGT2,  LDGT,  HDGV,  LDDV,  LDDT,  HDDV,  MC,  and  All  Veh.   The
remaining lines  in the  output  each consist of  an  identifier  at
left, with the values for that line, for  each of  the ten vehicle
types or groups,  following under the appropriate headings.

     The next  line  is "Veh. Speeds"  with values entered  only  in
the  eight  columns  for  which  vehicle  average  speed  is  used  to
correct the  emission  factors.   The next  line  is "VMT  Mix:"  with
VMT  fractions  by   vehicle  class  entered  in  the  appropriate
columns.    (No speed  or  VMT  Mix  values  will   appear   under  the
combined LDGT1 and LDGT2 "LDGT" column or the "All Veh" column.)

     The next  line  reads "Composite Emission Factors (Gm/Mile)."
This  line  precedes  a  set of  one  to  eight  lines  of  emission
factors,  depending  on the pollutants  to  be printed  (PRTFLG)  and
whether  component   HC  emission   factors   are   to   be  printed
(HCFLAG) .  If  all  eight  lines  appear,  they are  in the following
order:

     Label               Content

     Total HC:           Total  or Non-methane HC emission factor
                          (EF),  including all components (whether
                          or not they are listed individually)
     Exhaust HC:          Exhaust HC component EF
     Evaporative  HC:     Evaporative HC component EF
                          (includes crankcase emissions)
     Refuel  L HC:         Refueling loss HC component EF
     Running L HC:        Running loss HC component EF
     Rsting  L HC:         Resting loss HC component EF
     Exhaust CO:          Exhaust CO EF
     Exhaust NOx:         Exhaust NOx EF
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                               3-41
     Unless  the idle  emission factors have  been  requested,  this
completes  the  block for an  individual  scenario.   If  IDLFLG  = 2,
indicating  that  idle  emission  factors  are  to  be printed,  the
following  identifying  line  is   printed:   "Hot  Stabilized  Idle
Emission  Factors  (Gm/Hr)".   This  is  followed  by  one  to  three
additional  lines,  depending  on  the  pollutants  to  be  listed.
These lines are  labeled "Idle HC:", "Idle CO:", and "Idle NOx:".

     If  the expanded  evaporative  output  is  selected,  then  the
last  block of  output  will  contain  the  detailed  evaporative  HC
emission  factors by source, in  units appropriate  for  each.   This
option  is accessed  by setting  the  HCFLAG  in  the Control  Data
section  of  the input  to  "3."   The  standard OUTFMT  =  3  output
discussed  above  is  printed  first,    followed  by  the  expanded
evaporative emission factor output.

     The  identifying line  "Evaporative  Emissions  by Component" is
printed  first,  with the following  additional information on  the
first  two  lines:   Weathered  RVP,  Hot Soak  Temp,  Running  Loss
Temp,  and units  (Hot  Soak:   g/trip, Diurnals  &  Multiples:   g,
Refueling:   g/gal,  Running  Loss:   g/hr,  Crankcase:   g/mi).   Six
additional  lines of emission  factors are then printed,  lined up
under  the  column  headings  for   vehicle  type  from the  standard
emission  factor portion  of  the output.   These  are   labeled  in
order:  Hot  Soak,  Diurnal,  Multiple,  Refueling,  Running Loss,  and
Crankcase.  The  use  of  these evaporative  emission factors may be
required  for development  of inventories  that  are spatially  and
temporally  allocated,   as   required  for  input  to  many  Airshed
models.

     3.3.4  80-Column Descriptive Format (OUTFMT =  4)

     If  OUTFMT =4,  a well-annotated  descriptive format  output
similar  to that  described in section  3.3.3   is  produced.   This
format  is  also  designed  for  ease  of  visual  inspection,  with
complete  labeling  and  heading information.   The 80-column  width
allows  this  format to be  printed  in  portrait format  (vertically)
on standard 8.5 x 11 paper.

     The exact content of the report  is determined by  a number of
flag  settings.  Information  applicable  to  the  entire  run  (all
scenarios) is  listed  first,  followed  by  a  series  of  blocks,  one
per scenario evaluated.  The scenario output  blocks are separated
by solid  lines.  Example  4  in  Chapter 5 is  an illustration  of
this type of output.

     This  output follows  the  order  of information presented  in
section  3.3.3   above,  with  additional  lines  and  minor  format
changes   required   in  some   cases  to  accommodate  all  of   the
information in the narrower overall width.  Refer to Example  4  in
section 5.1.1 and the descriptions provided  above.
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                               3-42
     3.3.5  By Model Year Output

     The  last form  of  formatted output  report  available through
MOBILE4.1  is  the  by  model  year  option.   In  this   option,  the
112-column  descriptive  output  discussed  in  section  3.3.3  is
produced, followed by  additional tables  providing  information on
the  relative  contributions of  vehicles  of each  given model year
in the  calendar  year fleet  to  the overall fleet emission factor
for  each  vehicle type.  The  user  can select  which vehicle types
the  by model  year  tables  are  produced  for  through  the  values
assigned  to  the by  model year  inclusion  vector,  discussed  in
section 2.2.16.

     These  tables  (one table   per  vehicle  type  selected,  per
scenario) contain the following information:

     First,   the  title  of  the  MOBILE4.1  run  (as entered  by  the
user for  "PROJID"  in the Control section) and the  Scenario title
(as  entered  by  the  user on the Local Area  Parameter record)  are
echoed back as  identifiers.   The next two lines  give the vehicle
type for  which  the  table  is  applicable  and the  date of emission
factor evaluation (January  1,  CY,  where  CY is the  calendar year
of evaluation entered  by  the  user) .   The rest  of  the  table is
19 columns  wide  by  28  rows  long,  with  the  first  two  rows
consisting  of column  headings  and  the  last  row containing sums
for  some  of  the  column entries.  The remaining 25  rows represent
the  25  model  years  of  vehicles,  ending  in the  CY of evaluation,
in reverse order (newest vehicles first).

     The  first three  columns  (L to  R)  are labeled  "Model  Year",
"TF",  and "Miles".   Model  Year is  the  model  year  to  which  the
other values  of  the row apply.   TF is the  travel  fraction.   It
combines  the  registration distribution  by  age  and  the  annual
mileage accumulation  rates  by  age  to determine  the  fraction  of
all  vehicle  miles  travelled  (VMT)  by  the given vehicle  class
accounted  for  by  vehicles  of  that  row's  model  year  in  the
evaluated calendar year.   The TFs serve  as the  weighting factors
to  combine   the  model  year-specific  emission  factors  into  a
specific  vehicle   type's   fleetwide   emission   factor.    Miles
represents the average odometer mileage of vehicles  of model year
MY on January 1  of  calendar year CY, based on the average  annual
mileage accumulation rates  by age used in the model.

     The next eight  columns  are all  spanned by the  heading  "HC",
followed by four columns each for  "CO"  and "NOx".  The HC columns
contain information  on exhaust,  evaporative,  refueling,  running
loss, and resting loss  emissions,  while  CO and NOx deal only with
exhaust emissions.   The columns  common  to  all   three pollutants
have essentially the same descriptions.
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                               3-43
     "BEF4"  contains  the  average  exhaust emission  factor (g/mi)
for vehicles  of  model  year MY on January  1  of calendar  year CY.
This  emission factor  already contains the  following corrections
to  conditions   specified   by   the   user:    temperature,   fuel
volatility  (RVP),  operating  modes,  and  (if  applicable)  methane
offset,  inspection/maintenance  program  reduction,   and  open-loop
technology.   The  column  headed  "Tamper"  shows  the  tampering
offset   (emission   factor  increase   due   to  tampering),   also
corrected   for   temperature,   RVP,   operating   mode,   and   (if
applicable) open-loop technology.  The  tampering  offsets  are only
produced  for vehicle  types  subject  to tampering  (LDGVs,  LDGTs,
and HDGVs).

     The  column  headed  "SALHCF"  is  the  value  of   the  combined
correction  factors  for  average  speed  and  "optional" corrections
(air  conditioning  use,  extra loading,  trailer  towing,   and  NOx
humidity correction).  If  none of  the optional correction factors
are used, then SALHCF is simply the speed correction factor.

     For CO  and  NOx,  the  last  column  labeled  "FER" is  then  the
average  contribution  to  the  exhaust  emission  factor for  vehicles
of model year MY in calendar year CY.   This is calculated as:

     FER - (BEF4  + Tamper) * SALHCF *  TF.

Thus the FERs can be summed to obtain  the  exhaust emission factor
for that vehicle type  as shown in the preceding portion  of  the
output.

     For  HC,  the  remaining  columns  are   model  year-specific
emission factors  for  the  other  components  of HC  emissions.   The
column   "Evapor"   represents  the  combined  evaporative  emission
factor  (hot  soak,  diurnals, multiple  diurnals,   and crankcase),
including any offsets due  to  tampering.  The  column  "Refuel,"  for
gasoline  vehicles  only,  is the  model  year-specific  refueling
emission factor,  reflecting  Stage II  and/or  onboard VRS  control
if  applicable.   "Runnin"  and "Restin" are  the  running  loss  and
resting  loss  model  year-specific emission factors,  respectively,
for gasoline vehicles only.  The  FER for HC is then calculated as:

FER »  <[(BEF4+Tamper)*SALHCF]+(Evapor+Refuel+Runnin+Restin)> * TF

     Modelers who wish to use the by model year  emission .factors
for some analyses  and  have  additional questions  not  addressed
above  are encouraged to contact  EPA for additional assistance.
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                            Chapter 4

                    MOBILE4.1  IMPLEMENTATION

4.0  INTRODUCTI ON

     This chapter  contains  information on  the MOBILE4.1  program
diskettes and tapes,  and other information that may  be  useful  to
users  interested  in   the   computer  resource  requirements   of
MOBILE4.1, to users  implementing MOBILE4.1 on  their  own computer
systems,   and  to  users  who   are   considering making   software
changes.    It  also  contains  instructions  on  how   to  port  the
mainframe version  of  the code  to  personal  computers (Macintosh,
and IBM-style computers, such as PC-AT, PS-2,  or clones).


4.1  MOBILE4.1 TAPE

     The MOBILE4.1 tape released by EPA contains four files.   The
first  file  is the MOBILE4.1  source code in  mixed-case  lettering
(upper and  lower).   The second  file is exactly the  same  as  the
first  file,   except  it  is   an  uppercase-only  lettering version.
This second file has been provided  in  the event some  systems have
difficulty with  lowercase  characters.   The mixed-case version is
more easily read than the all-uppercase version.

     The third file is a copy of the input  files used to generate
the  User's  Guide  examples  of Chapter  5,   in  uppercase.   These
examples  can  be  used  to  verify  that  MOBILE4.1   is  operating
properly when installed on a new system.

     The  fourth  file  on the  tape  is  set  of  standard  parameter
inspection  and  maintenance  (I/M)  program  credits  applicable  to
high-altitude  areas.    The  I/M  credits stored in the  MOBILE4.1
code are applicable only to low-altitude  areas.   This   file  has
the  same structure as  is  used for the credits contained  in  the
code,  but  for  high-altitude  areas.   See   section  2.2.5  and
Appendix 2A.

     Other characteristics  of  the  MOBILE4.1 tape are presented in
Table  4.1-1.
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                               4-2


                           Table 4.l-i

                 MOBILE4.1 Tape Characteristics

      Density:        1600 bpi      Character Set:  EBCDIC
      Blocking:       3500          Total Length:   504.11 feet
      Record Length:   140          Unlabeled

 File                             Number of  Block   Tape Length
Number  	Description	   Records   Count     (Feet)

  1     MOBILE4.1 Source Code      26,233     1050     248.62
        (Mixed-case letters)

  2     MOBILE4.1 Source Code      26,233     1050     248.62
        (Uppercase)

  3     Input Files for User's        240       10       2.64
        Guide Examples

  4     I/M Credit Matrices           406       17       4.23
        (for high-altitude areas)


4.2  PROGRAM STORAGE REQUIREMENTS

     The  wide variety of computers  and system configurations  in
use prohibits  a  precise  statement of main storage requirements on
each    system.     Nevertheless,    the    following    should   be
representative of the requirements of MOBILE4.1 on most systems.

                          Kilobytes    32-bit memory words

     Source Code             1108            283,648
     Object Code              928            237,568

     The  standard  convention  of  1 kilobyte = 1024 bytes  is used.
The values were obtained from the  implementation  of MOBILE4.1 on
the Michigan  Terminal  System at Wayne State University,  based on
an Amdahl  5890-180E computer.

4.3  PROGRAM  EXECUTION TIME

     MOBILE4.1  requires  slightly more  time to  process scenario
records than  did MOBILE4.  This was  expected due  to the extensive
revisions  made  to the  program,  including  the additions  of new
subroutines,   the   increased    complexity   of   many   of   the
computational  algorithms used,  and the added  provisions  for the
user to  supply additional types of  input  data.   Since relatively
few model  users  operate in a time-sharing environment, statistics
on  execution  time  and  comparisons   to  MOBILE4  are  not  presented
here.
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                                4-3


4.4  DEVIATIONS FROM FORTRAN STANDARD ANSI X3.9-1978

     MOBILE4.1  is based  on  the FORTRAN  language  standard  ANSI
X3.9-1978   published   by   the   American   National   Standards
Institute.  No  incompatibilities are  known  to  exist  between the
MOBILE4.1 code and that standard.
4.5  TYPICAL JOB STRUCTURE

     Since job control  language  (JCL)  is highly system-dependent,
this  manual  does  not  provide  detailed examples.   The  general
requirements  for  running  a  job are  outlined here.   Most  users
should have little difficulty  implementing  JCL to perform similar
functions.

     The  simplest job structure for most systems is shown below:

JCL to sign on the computer system
JCL to compile MOBILE4.1 FORTRAN source code
      (MOBILE4.1 FORTRAN source code)
JCL  to  assign  MOBILE4.1  I/O,  catalog  (link  edit),  and  run
MOBILE4.1
      (MOBILE4.1  input data)
     MOBILE4.1  uses I/O device  numbers stored  in  common  IOUCOM.
MOBILE4.1  I/O device assignments  are:

4  =  user-supplied  inspection/maintenance  (I/M) credits  (IOUIMD)
5  =  general  input  data  (IOUGEN)
6  =  formatted reports  (IOUREP)
6  =  diagnostic  messages  (IOUERR)
6  =  input  prompting messages  (IOUASK)

     Users can  change  these device  numbers by modifying  source
code data statements   initalizing  common  IOUCOM  in  Block  Data
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                               4-4


Subprogram  16.    Output  devices  only can  also  be  changed  by
assigning replacement numbers to  IOUNEW on line 1 of the  Control
data section, as discussed in section 2.1.2.

     The  job structure  illustrated  above  does  not  read  user-
supplied I/M credits.  Users can read I/M  credits  by entering the
data  from  another  I/O  device,   such  as  a disk file or  magnetic
tape.   Alternately,  users  can  merge the  credits or  rates  with
other  input  and change the  I/M  logical  I/O device  number  from 4
to 5 by revising BLOCK DATA Subprogram 16:

Change    DATA IOUIMD,IOUGEN,IOUERR,IOUASK/4,5,6,2*9/

 to       DATA IOUIMD,IOUGEN,IOUERR,IOUASK/5,5,6,2*9/.

Another  useful  change  (especially for OUTFMT  =  1   or  2)  might
alter  IOUREP  from 6 to some other  unused  unit number via IOUNEW.
Again, see section 2.1.2.


4.6   INSTALLATION AND EXECUTION OF
     MOBILE4.1 ON PERSONAL COMPUTER SYSTEMS

     4.6.1  Introduction

     Due to the increased utilization  of personal  computers (PCs)
by  many parties  involved  in emission  factor  modeling  and  air
quality  planning  functions,  EPA  has  developed  MOBILE4.1  to  be
compatible  to  the  greatest  extent possible  with  the  two  most
commonly used PC  systems:   Apple Macintosh and IBM PC-AT  and PS-2
(and  their  clones).   However,  since  the  development  of  the
program was performed  entirely  on mainframe  time-sharing systems,
some  differences  exist  between  the MOBILE4.1 program as developed
and  discussed in this  User's  Guide,  and  the  program  in  a  form
that  can  be  executed  on  PC   systems.   This  section  provides
instructions  for  downloading the  mainframe  version  of  MOBILE4.1
(e.g.,  from  MTS -at  Wayne  State or  from NCC)  to the PCs mentioned,
outlines  the code  changes  reguired  for  the  personal  computer
environment,  and  provides  installation  instructions for  the use
of diskettes obtained through EPA or NTIS.

      4.6.2  Downloading the Mainframe Version  of MOBILE4.1 to
            an Apple Macintosh or  IBM-Style Desktop Computer

      Due   to  the   system  dependency  of    some   steps,   these
instructions  may  not   cover  every  situation  encountered  in
downloading   MOBILE4.1.   Users   attempting   this  operation  and
encountering difficulties may contact EPA  for  assistance.

      The  directions  provided  in  this section  assume  that  the
Macintosh  being  used  has  1024K  bytes of free memory  (2048K is
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                               4-5


recommended),  a   hard-disk  drive,   and  ABSOFT   Corporation's
MacFORTRAN or MacFORTRAN/020 compiler.   The  assumptions made with
respect to IBM-style computers are  that  640K memory  is available
and that the LAHEY FORTRAN F77L compiler  is present.

     The  first  operation  necessary  is  to  port  the  MOBILE4.1
source code  to  the Macintosh  or IBM-style  unit.   To  accomplish
this transfer, an  error-checking  protocol  (such as KERMIT) should
be  used.   The MOBILE4.1  code should  be  transmitted so  that  an
ASCII  text  file,   with  no  hidden characters (such  as  tabs),  is
created.

     Once  transferred,  the  code must  be modified  slightly  to
accommodate  the   Macintosh  or   IBM-style  FORTRAN  environment.
These  required modifications  include file opening  statements and
screen/keyboard connections:

     1.   This instruction applicable to  both types of computer.

          Insert  the  following  lines controlling  file  I/O just
          before  the   statement   INERR=0  in  the  MOBILE4.1  MAIN
          program section:

                OPEN(5,FILE='M4INPUT',STATUS='OLD')
                OPEN(6,FILE='M40UTPUT',STATUS='NEW')

          File names  other that  "M4INPUT"  and  "M40UTPUT"  may  be
          used.    If so, the names used  should  be  substituted for
          "M4INPUT" and "M40UTPUT"   in reading  the  remainder  of
          this section.

     2.   This instruction applicable to  both types of computer.

          If  alternate  I/M credits  are  also to be  read  in (see
          section   2.2.5),  then  insert   the  following  line
          immediately after the  comment  statement  "User supplies
          alternate FTP I/M credits":

                OPEN(4,FILE='M4IMC',STATUS='OLD')

          A file name other that  "M4IMC"  may be used.   If so, the
          name used should be substituted for  "M4IMC"  in  reading
          the remainder of this section.

     3.   Finally,  alter  the  initialization  line  for   screen/
          keyboard   I/O   in   SUBROUTINE   GETIOU.     This   line
          currently reads:

                DATA IOUDEF/6,6,6/
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                               4-6


          This line should be altered to  read:

          For Macintosh:                      DATA IOUDEF/6,6,9/

          For IBM-style computers:            DATA IOUDEF/6,6,0/

          If the user  also wishes to  have diagnostic  (error  and
          warning)  messages appear on  the  computer  screen,  rather
          than being listed  in the  formatted  output file,  these
          lines should  be altered to  read:

          For Macintosh:                     DATA IOUDEF/6,9,9/

          For IBM-style computers:           DATA IOUDEF/6,0,0/

     These  changes  direct MOBILE4.1  to  always  read the  program
input from  a  file  called M4INPUT and to  always  write the  program
output to  a  file  called M40UTPUT.   If  the alternate  I/M  credit
data  modification   was  made,  then  the   alternate  credits  will
always be  read from  a  file  called  M4IMC.  These  changes  direct
all prompting (last digit change)  and/or diagnostic (middle digit
change) messages  to the screen  (logical  I/O device  unit  9  for
Macintosh, unit 0  for IBM-style machines).

     After these changes have been made,  invoke  the compiler.   If
your  unit  has  a  math coprocessor,  select  it  using the  OPTIONS
menu  (Macintosh) or by using the /E Lahey compiler option (IBM).

     When the compilation has  been completed,  the  heap  space  for
the resulting MOBILE4.1  application  must be adjusted.   To do this
on  a  Macintosh,   select the  MOBILE4.1   application  icon,  then
select the  GET INFO option from the Macintosh  Finder's file menu
(not  the  compiler's menu).    Note  the application  size value in
the lower right portion  of  the window.  If it is less than 1024K,
increase  it  to  1024K.    No  such  adjustment  is  required  for
IBM-style computers.   However, due to  the  size of MOBILE4.1, only
DOS  should   reside  in  the  640K  memory   of  the   computer.   The
MOBILE4.1 application is now ready for use.

      Before  running the program,  place  the MOBILE4.1  input data
in  a  file  called  M4INPUT.   Next,  check  to  be   sure  that  the
M40UTPUT  file  is  empty.    (If   M40UTPUT   contains  data   or
information you wish to  save,  simply rename it  so  that it  is not
overwritten  by the results  of  the pending  MOBILE4.1  run.)   To
execute  on  Macintosh,   launch   the  MOBILE4.1   application  by
double-clicking  its   icon.   To   execute  on   IBM-style,   type
"MOBILE41"  at the DOS prompt.  See section 4.6.3.
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                               4-7
    4.6.3  Installing and Executing MOBILE4.1 on Desktop Computers

     These instructions are to be followed in  loading  the program
from  diskettes  supplied by  EPA or  obtained through  NTIS.   With
minor  exceptions,  they  can  also  be  followed  by those  running
MOBILE4.1  as  downloaded from  a mainframe computer  (as described
in the preceding section).

     Note:   These  instructions are  nearly  identical  for  both
types  of  computer.  Differences are  noted when  applicable.   For
IBM-style machines,  DOS  commands that  the user  types in  are  in
boldface.  Messages  generated  by  the  computer  are in quotation
marks.

1.   In order to  load  the  contents of  the MOBILE4. l  diskette(s),
     you  must  have  2.4 MB   (2.4  megabytes)  of available  disk
     space.   Additionally,   for IBM-style computers,  memory  of
     640 KB RAM is required  for program operating space.  In most
     cases,  this  means  that   no  other  resident  software  (e.g.,
     TOPS)  can be  present;   only  DOS  should  be loaded  unless
     adequate memory is  available.

2.   After the  contents  of  the diskette(s) have  been  copied into
     your   computer,  they   must  be   decompressed.     This   is
     accomplished  by  typing  M41   (IBM-style  machines),  or  by
     double-clicking on  the M41.CPT icon (Macintosh).

     The   following  files  will   then  reside   in  the  MOBILE41
     directory on an IBM-style computer:
       File Name

      MOBILE41.FOR

      MOBILE41.EXE
      COMPILE.BAT
      IMCHI.DAT
      EXINx.TXT

      EXOUTx.TXT
           Contents
Complete FORTRAN source code
  (including comments)
Executable (object) code
LAHEY FORTRAN compiler instructions
Alternate high-altitude I/M credits file
User Guide example input files
  (x = 1, 2, ...,  7)
User Guide example output files
  (X = 1, 2, ...,  7)
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                               4-8
    On a Macintosh, the following  files  will  be available in the
    MOBILE4.1 folder:
        Name
    Mobile4.1.FOR

    Read Me M41.FOR
    Mobile4.1
    Read Me

    Mobile4.1/020

    Read Me /020

    f77.rl

    mSl.rl

    IMCHI.DAT
    M41 Examples
                        Contents
                Complete FORTRAN source code
                   (including comments)
                Read file concerning the source code  file
                Executable  (object) code
                Read file concerning the Mobile4.l
                   object code  file
                Executable  (object) code,  for use with  a
                   math  co-processor (faster execution times)
                Read file concerning the Mobile4.1/020
                   object code  file
                Library file required  for  use of Mobile4.1
                   and Mobile4.1/020
                Library file required  for  use of
                   Mobile4.1/020
                Alternate high-altitude I/M credit  file
                Folder  containing seven example  input and
                   output files (EXIN.TXT and
                   EXOUT.TXT, x = 1, 2,  ...,7)
     It  is   recommended   that  the  files  f77.rl  and  m81.rl   be
     relocated from the MOBILE4.1 folder to  the  system folder  on
     your hard disk.  They must be  present  for the  object  code  to
     run properly.

     In order to execute  a MOBILE4 . 1 run:

     On a Macintosh, launch the MOBILE4.1  application by  double-
     clicking the icon  (Mobile4.1  or Mobile4 . 1/020) .

     On  an  IBM-style  machine,  when  prompted by DOS  ("C:>"   or
     similar), type

          MOB I LE41

     and return.

     If enough  memory  is available  for  the  program to  operate,
     the program will respond:

          "Interactive  input  mode  (Y/N)?"

     If you wish to enter the  input data in  an  interactive  mode,
type "yes" or
                        and  return,  then follow steps 9-15.   If
     you have  the  input data  in  a file  (recommended),  type  "no"
     or "N" and return,  then follow steps 5-8.
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                               4-9


         Steps 5-8:   Not using interactive data entry:

5.    The program will  respond with:

          ***********    MOBILE4.1 DRIVER   **********"

          "Enter number of MOBILE4.1 calls:"

     Type  in  the  number  of  MOBILE4 . 1  runs that  you intend  to
     execute,  then return.  Allowable values  are l to 999.   Each
     run can consist of any number of scenarios.

6.    The program will  respond:

          "Please enter the MOBILE4.1 input filename:"

     For IBM-style machines,  respond with  any valid DOS  file name
     [ 1 to 8  characters  (file name),  followed by  optional  period
     and 1  to  3  characters  (file  name extension); for  example,
     M4INPUT.A], then  return.   For  Macintosh,   respond  with  any
     valid file  name.   The input data  does not  have  to be  in a
     file  called  M4INPUT.   The  file  can  contain  up  to  999
     complete MOBILE4.1  input  data  files.   If more than  one input
     data set is in the file, the data sets must  be  separated by
     a line of zeroes:
     0000000000000000000000000000000000000000000000000000000000000

7.    The program will  respond:

          "Please enter the MOBILE4 . 1 output filename:"

     Respond  with  any  valid  file name  (any valid DOS file  name
     for IBM-style  machines), then  return.   The  output  does not
     have  to  be directed to  a  file  named  M40UTPUT.   The  file
     named  must  not   exist   prior  to  the  execution  of  this
     MOBILE4.1 run.   MOBILE4.1 will create,  open,  name,  and write
     to  this  file  in  executing.  No appending  to  existing files
     is permitted.

8.    The  program  will   then  execute.    No  messages   will  be
     generated  until   execution  is  completed.   Depending  on the
     number of  scenarios and the speed of the computer,  this may
     take  30  seconds  or   longer.    The  program  will  signal
     completion of the run by issuing this message:
          "Run #  INERR = "
          "DRIVER calls completed."
07/91

-------
                              4-10


    where   = the  number of the  run (entered at step 5), and
      =  the number of  errors  detected in the  input data set.
    Error  messages  will be  in  the file  named to  receive the
    output  in  step  7.   If  x  _>  1,  the program  may  not have
    generated the  desired  emission factors.   See  Chapter  3 for
    discussion  of  error  messages.


      Steps 9-15:  Using interactive mode of data entry:

 9.  The  program will  respond  with:

     ***********   MOBILE4.1 DRIVER    **********"

     "Enter  number  of  MOBILE4.1  calls:"

    Type in  the  number of  MOBILE4.1  runs that  you intend  to
    execute,  then return.  Allowable values are  1  to 999.  Each
     run  can consist of  any number of scenarios.

10.  The  program will  respond:

          "Please enter  the MOBILE4.1 output  filename:"

     Respond  with  any valid  file  name  (any valid  DOS file name
     for  IBM-style machines),  then return.   The output data does
     not  have to  go  to  a  file named  M40UTPUT.   The file named
    must not exist  prior to  the  execution   of  this  MOBILE4.1
     run.  MOBILE4.1  will create,  open,  name,  and  write to this
     file  in  execution.   No  appending  to  existing  files   is
     permitted.

11.   The  program then will expect you  to enter the value  of  the
     PROMPT flag  (see section 2.1.1).   You  will not  be  prompted
     for  this value;  you should enter  either  "2"  or "4," then
     return.  (The value  of PROMPT  must be either 2 or 4,  as  you
     have chosen interactive data entry.)

12.   Whether  "2"  (vertical data  entry)  or  "4"  (horizontal data
     entry)  is chosen for PROMPT,  the program may respond with
     which serves as  a  FORTRAN control character,  or  the  program
     may  "jump"  to a new  screen.   The reaction  to  the  control
     character is system-dependant.

13.  The  program  will then prompt  you  for  the remaining  input.
     (Prompting  messages  are  discussed in  section 3.1.)   Enter
     the  appropriate  input  data  in  response to each  prompt  then
     return.
07/91

-------
                               4-11
14.   After you  have  entered all  of  the  Scenario section  input
     data, the program  will respond  by prompting  for the  first
     record of  the next scenario  (calendar  year,  region,  etc.).
     Enter  a  zero  ("0")  to  indicate  that  you  have  finished
     entering  new data.

15.   The  program  will   then  execute.   No  messages   will   be
     generated until  execution is  completed.   Depending on  the
     number of scenarios  and the  speed of the computer,  this  may
     take  30   seconds  or   longer.    The  program  will  signal
     completion  of the run by issuing  this message:

          "Run tt  INERR = "
          "DRIVER calls completed."

     where  =  the  number of the run  (entered  at step  5),  and
       =  the  number of  errors  detected in the  input  data set.
     Error messages  will  be in  the  file  named  to   receive  the
     output in  step  10.    If  x  >_ 1,  the  program may  not  have
     generated the desired emission factors.  See  Chapter  3  for
     discussion of error messages.
07/91

-------
                               4-12
4.7  MOBILE4.1 ON THE NCC SYSTEM

     For those  users with access to the  National  Computing Center
(NCC), MOBILE4.1 has been  installed there.   This  is  the  mainframe
version of  the  program, and  is operated as  described through the
rest of this document.   File names and contents are given below:
         File Name

         KADSAME.M4KM41)
         KADSAME.LOAD(M41)
         KADSAME.M41(EXUG)
         KADSAME.M4B(IMCHI)
Contents

MOBILE4.1 Source code
MOBILE4.1 Object code
MOBILE4.1 Example runs (I/O files)
High-altitude area I/M credits
4.8  MOBILE4.1 ON THE MTS SYSTEM

     For those users  with access to the Michigan  Terminal System
(MTS),  MOBILE4.l  can  be accessed  there.   This is  the mainframe
version of  the program,  and is operated as described  through the
rest of this document.  File names and contents are given below:
         File Name
SFUT : M4 .
SFUT:M4.
SFUT : M4 .
SFUT:M4.
SFUT : M4 .
SFUT : M4 .
l.S
l.L
l.C
1 . D-UG
1 . R-UG
l.D-HI
Contents

MOBILE4.1 Source code
MOBILE4.1 Object code
Command file to run the model
Input file for example.runs
Output file for example runs
High-altitude area I/M credits
4.9  PROGRAM UPDATE  INFORMATION

     EPA  expects MOBILE4.1 to  undergo future revision to correct
possible  errors,  improve  program  performance,   and  incorporate
changes  in the methodology.  Users  who  wish to submit changes or
corrections  can  mail these  to  the  EPA  Motor  Vehicle  Emission
Laboratory  in  Ann Arbor, at the  address given  at the end of this
section.

     A  list of  program  errors  and  User's  Guide  corrections will
be   compiled,   if  necessary,   and   distributed   to  EPA  Regional
Offices.  EPA  does not currently  intend  to support a user mailing
list for  automatic  distribution  of  these corrections.   Users
should  contact their Regional  Offices from  time to  time.   Users
who  wish to do  so may  submit  the following Update Request form.
In  the  event a complete mailing  list is  assembled,  they will be
included  and sent  any published changes  to  MOBILE4.1.
 07/91

-------
                               4-13


                     MOBILE4.1 UPDATE REQUEST
Mail to:        MOBILE4.1 Emission Factor Project
                U.S. EPA Motor Vehicle Emission Laboratory
                Emission Control Technology Division
                Test and Evaluation Branch
                2565 Plymouth Road
                Ann Arbor, Michigan  48105
Name and Address of User:
                CITY	STATE	

                ZIP	


Name(s)  and telephone number(s)  of individual(s)  we may  need to
reach to respond to questions:
                             MOB ILE4.1
 07/91

-------
                               4-13
                     MOBILE4.1  UPDATE REQUEST
Mail to:        MOBILE4.1 Emission Factor Project
                U.S. EPA Motor Vehicle Emission Laboratory
                Emission Control Technology Division
                Test and Evaluation Branch
                2565 Plymouth Road
                Ann Arbor, Michigan  48105
Name and Address of User:
                CITY	STATE

                ZIP
Name(s)  and telephone number(s)  of  individual(s)  we may  need to
reach to  respond to questions:
                             MOB ILE4.1
 07/91

-------
                            Chapter 5

                        MOBILE4.1  EXAMPLES
5.0  INTRODUCTI ON
     Seven examples  are  provided to  illustrate  various  aspects of
MOBILE4.1.  The  user is  encouraged  to try  two or  more  of  these
examples to ensure that the model as compiled is running properly.


5.1  EXAMPLES

     The MOBILE4.1 examples are summarized in Table 5.1-1.
                            Table  5.1-1

             Summary Description of  MOBILE4.1  Examples
Example

 1-5
    1
    2
    3
    4
    5
Title

Output choices
          Replacement
           Of MOBILE4.1
           data
          Anti-tampering
            program
Content

Emission rates evaluated on January 1
  of 1980, 1988, 1990 (1-4 only), and
  2000 (1-4 only);  onboard VRS for
  light-duty gas vehicles and trucks
  starting in MY 1989.

OUTFMT = 1 (221-column numeric)
OUTFMT = 2 (140-column numeric)
OUTFMT = 3 (112-column descriptive)
OUTFMT = 4 ( 80-column descriptive)
OUTFMT = 5 (by model year tables
  plus 112-column output)

Emission rates evaluated on January 1
  of 1980, 1988, 1990, and 2000;
  user-supplied alternate
  registration distributions and
  annual mileage accumulation
  rates by age.

Emission rates evaluated on January 1
  of 1980, 1988, 1990, and 2000,
  with an anti-tampering program
  implemented January 1, 1984.
                                                                 07/91

-------
                               5-2
     5.1.1  Output Choices

     Examples 1 through  5 illustrate  the  five choices  of  output
formats available from MOBILE4.1.   Each  of these  examples  models
emission factors for 1/1/80,  1/1/88, 1/1/90,  and 1/1/00 using:

     default tampering rates  (TAMFLG=1)
     one average speed for all vehicle types  (SPDFLG=1)
     default VMT mix (VMFLAG=1)
     default registration distributions and annual mileage
       accumulation rates (MYMRFG=1)
     no new basic emission rate equations (NEWFLG=1)
     no inspection/maintenance program (IMFLAG=1)
     no additional correction factors for light-duty gas
       vehicles and trucks (ALHFLG=l)
     no anti-tamper ing program (ATPFLG=1)
     refueling emissions (from LDGVs, LDGTls,  LDGT2s
       only) controlled by onboard VRS starting with
       model year 1989 vehicles (RLFLAG=3)
     local area parameter (LAP) record provided for
       each scenario (LOCFLG=1)
     MOBILE4.1 calculated temperatures for correction of
       emission factors, based on user-supplied minimum
       and maximum temperatures (TEMFLG=1)
     emission factors for all pollutants (PRTFLG=4)
     no idle emission factors (IDLFLG=1)
     total hydrocarbon emission factors (NMHFLG=1)
     separate listing of the components of HC emissions:
       exhaust, evaporative,  refueling, running loss,
       and resting loss (HCFLAG=2)
     FTP temperatures:  75°F (24°C), diurnal  temperature
       range 60° to 84°F (11° to 29°C)
     FTP operating mode fractions:  20.6/27.3/20.6
     Fuel volatility of 11.5 psi RVP for all  years
       (period 1 RVP = period 2 RVP)

     The  output  from  example  1  is shown on  two  pages;  if this
output  is directed  to a  file,  each  line is  220  columns  wide.
Only  the first  two calendar  years (1980  and  1988)  are included
with Example 5 due to the length of  the  output produced.  Each of
the  five  choices  of  formatted  output  report  is  discussed  in
Chapter 3.
                                                                07/91

-------
                               5-3


     Note  that  the  calendar  year  2000  emission  factors  are
preceded  by a  warning message  regardless of  the output  format
chosen.   Users  may wish to  reassign  the  logical  I/O device  for
messages  to a  different  file than is  designated to  receive  the
emission  factors,   particularly   if  one  of  the  numeric  output
options has been chosen and  the  results are to be used  as input
for another program, in order to avoid the need  for  examining  and
editing the output file.  See section  2.1.2.
                                                                07/91

-------
1           PROMPT
MOBILE4.1 UG  EXAMPLE
           TAMFLG
           SPDFLG
           VMFLAG
           MYMRFG
           NEWFLG
           IMFLAG
           ALHFLG
           ATPFLG
3          RLFLAG
1           LOCFLG   -
1           TEMFLG   -
1           OUTFMT   -
4          PRTFLG
1           IDLFLG
1           NMHFLG
2          HCFLAG   -
89 2221        IOBMY,
1  80  19.6 75.0  20.6
SAN FRANCISCO CA C
1  88  19.6 75.0  20.6
SAN FRANCISCO CA C
1  90  19.6 75.0  20.6
SAN FRANCISCO CA C
1  00  19.6 75.0  20.6
SAN FRANCISCO CA C
 1: OUTFMT =  1  (LONG  (220  COLUMN)  NUMERIC OUTPUT FORMAT)
  READ IN LOCAL AREA  PARAMETERS AS 2ND REQ SC REC
  CALCULATE EXHAUST TEMPERATURES
  MOBILE4 210 COLUMN  3  DP NUMERIC OUTPUT FORMAT
  PRINT HC COMPONENTS
 IVOB
27.3 20.6
60.  84. 11.5  11.5  88
27.3 20.6
60.  84. 11.5  11.5  88
27.3 20.6
60.  84. 11.5  11.5  88
27.3 20.6
60.  84. 11.5  11.5  88
   1ST REQ SC REC:  IREJN.ICV.
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICV
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST.TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
SPD(1),AMBT,PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,I USESY
SPD(1).AMBT.PCCN.PCHC.PCCC
,TEMMAX,RVPBAS,RVPIUS,I USESY
SPD(1).AMBT.PCCN.PCHC.PCCC
.TEMMAX.RVPBAS.RVPIUS,IUSESY
SPD(1).AMBT.PCCN.PCHC.PCCC
.TEMMAX.RVPBAS.RVPIUS. IUSESY

-------
MOBILE4.1 UG EXAMPLE 1: OUTFMT = 1 (LONG  (220 COLUMN) NUMERIC OUTPUT FORMAT)
R
e
g
1





1
1
1





1
1
1





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1
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80





80
80
88





88
88
90





90
90
Vehi c 1 e Speeds
19.





19.
19.
19.





19,
19,
19





19
19
6/19.





.6/19.
.6/19,
.6/19.





.6/19
.6/19
.6/19





.6/19
.6/19
.6/19.





.6/19.
.6/19.
.6/19.





.6/19.
.6/19.
.6/19.





.6/19.
.6/19.
6/19.





6/19.
.6/19.
6/19.





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,6/19,
.6/19.





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.6/19,
6/ 19. 6/





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,6/ 19. 6/





.6/19. 6/
.6/19. 6/
.6/ 19. 6/





.6/19. 6/
.6/19. 6/
19





19
19
19





19
19
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19
19
.6/19.





.6/19,
.6/19,
.6/19.





.6/19,
.6/19,
.6/19,





.6/19
.6/19,
,6/19.





.6/19.
.6/19.
.6/19.





.6/19,
.6/19,
.6/19,





.6/19
.6/19
6





.6
.6
.6





.6
.6
.6





.6
.6
Amb.
Tmp
78





78
78
78





78
78
78





78
78
Cold/Hot Start i
20,





20.
20,
20,





20,
20,
20





20
20
.6





.6
.6
.6





.6
.6
.6





.6
.6
27,





27
27
27





27
27
27





27
27
.3





.3
.3
.3





.3
.3
.3





.3
.3
20.





20,
20,
20.





20,
20,
20,





20
20,
.6





.6
.6
.6





.6
.6
.6





.6
.6
Alt.
in Ft .
500.





500.
500.
500.





500.
500.
500.





500.
500.
P
o
1
1
X
V
R
T
S
2
3
1
X
V
R
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S
2
3
1
X
V
R
T
S
2
3
LDGV
8.
4.
2
0,
1 ,
0,
54,
3,
4
2
1
0
0
0
29
1
4
1
1
0
0
0
25
1
.394
.342
.438
.368
. 126
. 120
.957
.111
.684
.275
.247
.262
.784
.116
.070
.700
.087
.909
.097
.217
.752
.111
. 229
.439
LDGT1
9.
5.
2.
0.
1 .
0.
62,
3,
6
3,
1 ,
0,
0.
0,
40,
2
5
2
1
0
0,
0
34
1
,670
, 161
,842
.433
.131
. 103
.885
.257
. 166
.383
.571
.331
.780
.101
.562
. 145
.216
.867
.294
.274
.683
.097
.050
.892
LDGT2
16
7
6
0
2
0
82
4
8
4
2
0
1
0
47
2
7
3
2
0
0
0
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2
.642
.844
.058
.440
. 199
. 102
.036
.682
.484
. 182
.823
.335
.044
.101
.979
.670
. 141
.564
.291
.281
.907
.098
.327
.277
Composite Emission Factors
LDGT HDGV LDDV LDDT
1 1
6
3
0
1
0
69
3
6,
3
1 ,
0,
0
0
43
2,
5,
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0
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2,
.979
.049
.907
.436
.485
. 102
.229
.729
.938
.649
.988
.332
.868
.101
.031
.320
.831
.090
.613
. 276
.755
.097
.056
.015
29,
14,
12,
0,
2,
0
226
7
18
6,
8
0,
1
0,
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5,
15
5
7,
0
1
0,
105,
5,
.666
.079
.288
.615
.521
. 163
.273
.387
. 129
.954
.602
.537
.890
. 147
.803
.963
. 208
.670
. 254
.525
.623
. 136
.695
.781
0,
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1 ,
0
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.991




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.794




. 725
.769
.932
.932




.898
.866
M120 Warning: MOBILE4.1 does not model most  1993 and  later Clean Air Act
              requirements; Emission  Factors  for CY  1993  or  later are affected.
1  0 19.6/19.6/19.6/19.6/19.6/19.6/19.6/19.6
     19.6/19.6/19.6/19.6/19.6/19.6/19.6/19.6
     19.6/19.6/19.6/19.6/19.6/19.6/19.6/19.6
78





78
78
20.6





20.6
20.6
27.3





27.3
27.3
20.6





20.6
20.6
500.





500.
500.
1
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V
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T
S
2
3
2. 741
1 .002
0.885
0.041
0.726
0.087
15.394
0.779
3.383
1 .738
0.874
0.070
0.617
0.084
18.908
1 .240
3.726
1 .855
1 .037
0.073
0.679
0.083
21.011
1 . 286
3.484
1 . 773
0.922
0.071
0.635
0.083
19.530
1 .254
9.032
2.882
4.458
0.488
1 . 108
0.095
44.891
4.662
0.629
0.629




1 .596
1 .367
0.924
0.924




1 .835
1 .681

-------
                                         Vehi c1e Mix
 HDDV     MC   All  Veh LDGV  LDGT1  LDGT2 HDGV  LDDV  LDDT  HDDV   MC    Scenario  Title
5.
5.




16
30
3
3




13
21
3
3




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20
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.483




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0.





0,
0,
.005





.005
.005
.013





.013
.013
.009





.009
.009
0.





0.
0.
0.





0.
0.
0.





0.
0.
,001





,001
,001
.003





.003
,003
,002





,002
,002
0





0
0
0





0
0
0,





0,
0,
.052





.052
.052
.072





.072
.072
.076





.076
.076
0,





0
0
0





0
0,
0,





0.
0,
.011





.011
.011
.009





.009
.009
.008





.008
.008
SAN





SAN
SAN
SAN





SAN
SAN
SAN





SAN
SAN
FRANCISCO





FRANCISCO
FRANCISCO
FRANCISCO





FRANCISCO
FRANCISCO
FRANCISCO





FRANCISCO
FRANCISCO
CA





CA
CA
CA





CA
CA
CA





CA
CA
                                                                                                                                     Ul
                                                                                                                                      I
 2.209   5.479   3.141 0.589 0.191 0.080 0.038 0.002 0.002 0.092 0.007  SAN  FRANCISCO  CA
 2.209   2.099   1.399
         2.940   0.958
                 0.062
                 0.641
         0.440   0.080
11.385  21.437  17.244 0.589 0.191 0.080 0.038 0.002 0.002 0.092 0.007  SAN  FRANCISCO  CA
 9.697   0.830   1.880 0.589 0.191 0.080 0.038 0.002 0.002 0.092 0.007  SAN  FRANCISCO  CA

-------
1           PROMPT
MOBILE4.1 UG EXAMPLE
1           TAMFLG
1           SPDFLG
1           VMFLAG
1           MVMRFG
1           NEWFLG
1           IMFLAG
1           ALHFLG
1           ATPFLG
3          RLFLAG
1           LOCFLG   -
1           TEMFLG   -
2          OUTFMT
4          PRTFLG
1           IDLFLG
1           NMHFLG
2          HCFLAG   -
89 2221        IOBMY,
1  80  19.6 75.0  20.6
SAN FRANCISCO  CA C
1  88  19.6 75.0  20.6
SAN FRANCISCO  CA C
1  90  19.6 75.0  20.6
SAN FRANCISCO  CA C
1  00  19.6 75.0  20.6
SAN FRANCISCO  CA C
 2:  OUTFMT = 2 (SHORT  (139  COLUMN)  NUMERIC OUTPUT FORMAT)
  READ IN LOCAL AREA  PARAMETERS  AS 2ND REQ SC REC
  CALCULATE EXHAUST TEMPERATURES
  PRINT HC COMPONENTS
 IVOB
27.3 20.6
60.  84. 11.5  11.5  88
27.3 20.6
60.  84. 11.5  11.5  88
27.3 20.6
60.  84. 11.5  11.5  88
27.3 20.6
60.  84. 11.5  11.5  88
   1ST REQ SC REC: IREJN.ICY^
LAP REC: SCNAME,RVPAST.TEMMIN
   1ST REQ SC REC: IREJN.ICV,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC: IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC: IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
SPD(1)
.TEMMAX
SPD(1)
.TEMMAX
SPD(1),
,TEMMAX
SPD(1),
.TEMMAX
AMBT,PCCN,PCHC,PCCC
,RVPBAS,RVPIUS,IUSESY
AMBT,PCCN.PCHC,PCCC
,RVPBAS,RVPIUS,IUSESY
AMBT,PCCN,PCHC,PCCC
.RVPBAS.RVPIUS,IUSESY
AMBT,PCCN,PCHC,PCCC
,RVPBAS.RVPIUS,IUSESY

-------
MOBILE4.1 UG EXAMPLE 2: OUTFMT  =  2  (SHORT  (139  COLUMN)  NUMERIC OUTPUT FORMAT)
R
e
9
1





1
1
1





1
1
1





1
1
CY
80





80
80
88





88
88
90





90
90
Amb .
Tmp
78





78
78
78





78
78
78





78
78
Cold/Hot
20





20.
20.
20.





20.
20,
20,





20,
20,
.6





.6
.6
.6





.6
,6
.6





,6
,6
27





27
27
27





27
27.
27





27
27
Start
.3





.3
.3
.3





.3
.3
.3





.3
.3
20





20
20
20





20.
20
20





20
20,
.6





.6
.6
.6





.6
.6
.6





.6
.6
P
o
1
1
X
V
R
T
S
2
3
1
X
V
R
T
S
2
3
1
X
V
R
T
S
2
3
LDGV
8
4.
2
0.
1 .
0.
54.
3
4
2
1
0
0
0.
29.
1 .
4.
1 ,
1 .
0.
0.
0.
25,
1 .
.39
.34
.44
.37
. 13
. 12
.96
. 1 1
.68
.27
.25
.26
.78
. 12
.07
.70
.09
,91
. 10
.22
.75
. 1 1
.23
.44
LDGT1
9
5.
2
0
1 .
0.
62
3,
6
3
1
0
0
0.
40.
2.
5.
2.
1 .
0.
0.
0.
34.
1 .
.67
. 16
.84
.43
. 13
. 10
.89
.26
. 17
.38
.57
.33
.78
. 10
.56
. 14
.22
.87
.29
.27
.68
. 10
.05
.89
LDGT2
16.
7.
6.
0.
2.
0.
82.
4,
8.
4,
2.
0,
1 ,
0.
47.
2.
7.
3.
2.
0.
0.
0.
40,
2.
.64
84
.06
,44
.20
. 10
,04
.68
.48
. 18
.82
.33
.04
, 10
.98
.67
14
,56
,29
.28
.91
. 10
.33
.28
Composite Emission Factors
LDGT HDGV LDDV LOOT
1 1 .
6.
3.
0.
1 .
0.
69.
3.
6.
3.
1 .
0.
0.
0.
43.
2.
5.
3.
1 .
0.
0.
0.
36.
2.
.98
05
91
,44
,48
. 10
,23
,73
.94
.65
,99
.33
.87
. 10
.03
.32
.83
.09
.61
.28
.75
. 10
.06
.01
29.
14.
12.
0.
2.
0.
226.
7.
18.
6.
B.
0.
1 .
0.
128.
5.
15.
5.
7.
0.
1 .
0.
105.
5.
.67
08
.29
.61
.52
. 16
. 27
,39
, 13
,95
.60
.54
.89
. 15
80
96
.21
67
. 25
.53
62
. 14
,70
,78
0
0




1
1
0
0




1
1
0
0




1
1
.66
.66




.56
.51
.62
.62




.57
.57
.69
.69




.67
.63
0.
0.




2,
1 .
0,
0,




1 .
1 .
0.
0.




1 ,
1 .
.99
.99




. 13
.96
.79
.79




.72
.77
.93
.93




,90
,87
HDDV
5
5




16
30
3
3




13,
21 ,
3,
3,




13,
20,
.48
.48




. 24
.06
.40
.40




.95
.52
.03
.03




.30
.07
MC
9
6.
2.


0
33,
0
6
3
2,


0,
22.
0.
5.
2.
2.


0.
21 .
0.
. 71
,98
,29


.44
.63
.47
.36
.07
.85


.44
. 71
.80
.93
.57
.91


. 44
.95
.82
A 1 1 Veh
9
5
2
0
1
0
60
4
5
2
1
0
0
0.
34.
3.
4.
2
1
0
0
0.
29.
3
.63
.07
.91
.36
. 17
. 1 1
.70
. 74
.55
.82
.59
.26
.77
. 1 1
.31
.41
.82
.41
.37
. 22
.71
. 10
.62
. 15
LDGV
.688





.688
.688
.639





.639
.639
.628





.628
.628
Vehic
LDGT1LDGT2HDGV
. 142





. 142
. 142
. 152





. 152
. 152
. 163





. 163
. 163
.070





.070
.070
.076





.076
.076
.077





.077
.077
.031





.031
.031
.036





.036
.036
.037





.037
.037
le Mi
LDDV
.005





.005
.005
.013





.013
.013
.009





.009
.009
A
LDDT
.001





.001
.001
.003





.003
.003
.002





.002
.002
HDDV
.052





.052
.052
.072





.072
.072
.076





.076
.076
MC
.011





.01 1
.011
.009





.009
.009
.008





.008
.008






















Ln
1
00

M120 Warning: MOB1LE4.1 does not model  most  1993  and  later Clean Air Act
      78
   0  78
   0  78
              requirements; Emission  Factors  for  CY  1993  or later are affected.
           20.6  27.3
20.6





20.6
20.6
1
X
V
R
T
S
2
3
2
1
0
0
0
0
15.
0.
.74
.00
.88
.04
.73
.09
.39
,78
3
1
0
0
0
0
18
1 ,
.38
.74
.87
.07
.62
.08
.91
. 24
3,
1 ,
1 ,
0,
0,
0.
21 .
1 .
.73
.86
.04
.07
.68
.08
.01
.29
3.
1 ,
0.
0.
0.
0.
19.
1 .
.48
.77
.92
.07
.64
.08
.53
25
9.
2.
4.
0.
1 .
0.
44,
4.
.03
.88
.46
.49
. 1 1
.09
.89
.66
                                                                    0.63
1 .60
1 .37
                                                                           0.92
                                                                    0.63   0.92
1.84  11.39
1 .68
2.21   5.48   3.14 .589 .191 .080  .030  .002  .002  .092  .007
2.21   2.10   1.40
       2.94   0.96
              0.06
              0.64
       0.44   0.08
      21.44  17.24 .589 .191 .080  .038  .002  .002  .092  .007
9.70   0.83   1.88 .589 .191 .080  .038  .002  .002  .092  .007

-------
1           PROMPT
MOBILE4.1 UG  EXAMPLE
1           TAMFLG
1           SPDFLG
1           VMFLAG
1           MYMRFG
1           NEWFLG
1           IMFLAG
1           ALHFLG
1           ATPFLG
3          RLFLAG
1           LOCFLG   -
1           TEMFLG
3          OUTFMT
4          PRTFLG
1           IDLFLG
1           NMHFLG
2          HCFLAG   -
89 2221        IOBMY,
1  80  19.6 75.0  20.6
SAN FRANCISCO CA  C
1  88  19.6 75.0  20.6
SAN FRANCISCO CA  C
1  90  19.6 75.0  20.6
SAN FRANCISCO CA  C
1  00  19.6 75.0  20.6
SAN FRANCISCO CA  C
 3:  OUTFMT = 3  (LANDSCAPE  (112 COLUMN) DESCRIPTIVE OUTPUT  FORMAT)
  READ IN LOCAL AREA  PARAMETERS AS 2ND REQ SC REC
  CALCULATE EXHAUST TEMPERATURES
  PRINT HC COMPONENTS
 IVOB
27.3 20.6
60.   84. 11.5  11.5  88
27.3 20.6
60.   84. 11.5  11.5  88
27.3 20.6
60.   84. 11.5  11.5  88
27.3 20.6
60.   84. 11.5  11.5  88
   1ST REQ SC REC:  IREJN.ICV,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
SPD(1),AMBT,PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,IUSESY
SPD(1).AMBT,PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,IUSESY
SPD(1).AMBT,PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,IUSESY
SPD(1),AMBT,PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,IUSESY
                                                                                                                                          t_n
                                                                                                                                          I
                                                                                                                                          vo

-------
MOBILE4.1 UG EXAMPLE 3: OUTFMT  =  3  (LANDSCAPE  (112  COLUMN)  DESCRIPTIVE OUTPUT FO

Total HC emission factors  include evaporative  HC  emission  factors.
Cal.  Year: 1980
                        I/M Program:  No
                 Anti-tam. Program:  No
  Ambient Temp: 78.1 / 78.1 / 78.1 (F) Region: Low
Operating Mode: 20.6 / 27.3 / 20.6   Altitude:  500. Ft
SAN FRANCISCO CA
                      Period  1  RVP:  11.5
                                               Minimum Temp:   60.  (F)
                                               Period  2 RVP:  11.5
                                 Maximum Temp:  84.  (F)
                            Period 2 Start Yr:  1988
Veh. Type
Veh. Speeds
VMT Mix
LDGV
19.6
0.688
Composite Emission Factors
Total HC
Exhaust HC
Evaporat HC
Refuel L HC
Runing L HC
Rsting L HC
Exhaust CO
Exhaust NOX
Cal . Year: 1988

SAN FRANCISCO CA
8.39
4. 34
2.44
0.37
1.13
0.12
54.96
3.11
I/M
Ant i -tarn.

LDGT1
19.6
0. 142
(Gm/Mi le)
9.67
5.16
2.84
0.43
1.13
0.10
62.89
3.26
Program:
Program:

Period 1 RVP:
Veh. Type
Veh. Speeds
VMT Mix
Composite Emissi
Total HC
Exhaust HC
Evaporat HC
Refuel L HC
Runing L HC
Rsting L HC
Exhaust CO
Exhaust NOX
Cal . Year: 1990

SAN FRANCISCO CA
LDGV
19.6
0.639
on Factors
4.68
2. 27
1 . 25
0. 26
0.78
0.12
29.07
1 .70
I/M
Ant i -tarn.

LDGT1
19.6
0. 152
(Gm/Mi 1 e)
6.17
3.38
1 .57
0.33
0.78
0.10
40.56
2.14
Program :
Program:

Period 1 RVP:
Veh . Type :
Veh . Speeds :
VMT Mix:
LDGV
19.6
0.628
LDGT1
19.6
0. 163
LDGT2
19.6
0.070

16.64
7.84
6.06
0.44
2.20
0.10
82.04
4.68
No
No

11.5
LDGT2
19.6
0.076

8.48
4.18
2.82
0.33
1 .04
0.10
47.98
2.67
No
No

11.5
LDGT2
19.6
0.077
LDGT



1 1 .98
6.05
3.91
0.44
1 .48
0.10
69. 23
3.73
Amb i en t
Operat ing
Mi nimum
Period
LDGT



6.94
3.65
1 .99
0.33
0.87
0.10
43.03
2 .32
Ambi ent
Operat i ng
Mi n imum
Period
LDGT


HDGV
19
0

29
14
12
0
2
0
226
7
Temp :
Mode:
Temp :
2 RVP:
6
031

67
08
29
61
52
16
27
39
78. 1
20.6
60.
11.5
HDGV
19
0

18
6
8
0
1
0
128
5
Temp :
Mode :
Temp :
2 RVP:
6
036

13
95
60
54
89
15
80
96
78. 1
20.6
60.
11.5
HDGV
19
0
6
037
LDDV
19.6
0.005

0.66
0.66




1 .56
1.51
/ 78. 1 /
/ 27.3 /
(F)
LDDT
19.6
0.001

0.99
0.99




2.13
1 .96
78. 1 (F) Reg
HDDV
19.6
0.052

5.48
5.48




16.24
30.06
i on : Low
20.6 Altitude: 500
Maximum Temp: 84.
Period 2 Start
LDDV
19.6
0.013

0.62
0.62




1 .57
1 .57
/ 78. 1 /
/ 27.. 3 /
(F)
LDDT
19.6
0.003

0.79
0.79




1 . 72
1 . 77
78. 1 (F) Reg
20.6 Al t i t
Yr: 1988
HDDV
19.6
0.072

3.40
3.40




13.95
21.52
ion: Low
ude: 500
Maximum Temp: 84.
Period 2 Start
LDDV
19.6
0.009
LDDT
19.6
0.002
Yr: 1988
HDDV
19.6
0.076
MC
19.6
0.011

9.71
6.98
2.29


0.44
33.63
0.47

Ft .
(F)

MC
19.6
0.009

6.36
3.07
2.85


0.44
22.71
0.80

Ft .
(F)

MC
19.6
0.008
A 1 1 Veh



9 .626
5.070
2.910
0.364
1 . 167
0.114
60.699
4.745




A 1 1 Veh



5.547
2.822
1 .588
0.263
0.768
0. 106
34.312
3.415




Al 1 Veh


Composite Emission Factors  (Gm/Mile)
Total    HC:      4.09       5.22       7.14
                                                                                                                                       Oi
                                                                                                                                       t—»
                                                                                                                                       O
                                                 5.83
                                                          15.21
                                                                     0.69
                                                                               0.93
                                                                                         3.03
                                                                                                   5.93
                                                               4.816

-------
Exhaust HC :
Evaporat HC :
Refuel L HC :
Runing L HC :
Rsting L HC :
Exhaust CO:
Exhaust NOX:
1.91
1.10
0. 22
0.75
0.11
25. 23
1 .44
2 .87
1 .29
0.27
0.68
0.10
34.05
1 .89
3.56
2. 29
0. 28
0.91
0.10
40.33
2. 28
3.09
1 .61
0. 28
0.75
0.10
36.06
2.01
5
7
0
1
0
105
5
.67
.25
.53
.62
. 14
.70
.78
0.69




1 .67
1 .63
0.93




1 .90
1 .87
3.03




13.30
20.07
2.57
2.91


0.44
21 .95
0.82
2.410
1 .369
0.222
0.714
0. 102
29.616
3. 154
M120 Warning: MOBILE4.1 does not model most 1993 and later Clean Air Act
              requirements; Emission Factors for CY 1993 or later are affected.
Cal .  Year: 2000
                       I/M Program: No
                 Anti-tarn. Program: No
SAN FRANCISCO CA
                      Period 1 RVP: 11.5
Veh. Type:
Veh. Speeds:
VMT Mix:
Composite Emiss
Total HC :
Exhaust HC :
Evaporat HC :
Refuel L HC :
Runing L HC :
Rsting L HC :
Exhaust CO:
Exhaust NOX:
LDGV
19.6
0.589
i on Factors
2.74
1 .00
0.88
0.04
0.73
0.09
15.39
0.78
LDGT1
19.6
0.191
(Gm/Mi le)
3.38
1 . 74
0.87
0.07
0.62
0.08
18.91
1 .24
LDGT2
19.
0.

3.
1 .
1 .
0,
0,
0,
21 ,
1 ,
.6
080

.73
.86
.04
.07
.68
.08
.01
.29
Ambient Temp: 78.1
lerating Mode: 20.6
Minimum Temp: 60.
Period 2 RVP: 11.5
LDGT HDGV


3.
1 .
0.
0,
0.
0,
19
1 .


.48
.77
.92
.07
.64
.08
.53
.25
19.
0.
9.
2.
4
0
1 ,
0.
44
4
.6
.038
.03
.88
.46
.49
. 1 1
.09
.89
.66
/ 78.1 / 78.1 (F) Region: Low
/ 27.3 / 20.6 Altitude: 500. Ft.
(F) Maximum Temp: 84. (F)
Period 2 Start Yr: 1988
LDDV LOOT HDDV MC
19,
0.
0.
0.




1 .
1 .
.6
.002
.63
.63




.60
.37
19
0
0
0




1
1
.6
.002
.92
.92




.84
.68
19.
0.
2.
2.




1 1 .
9,
6
092
21
21




.39
.70
19.
0.
5.
2.
2


0
21
0
.6
.007
.48
. 10
.94


.44
.44
.83
Al 1


3.
1 .
0
0.
0
0,
17
1
Veh


.141
.399
.958
.062
.641
.080
. 244
.880

-------
1            PROMPT
MOBILE4.1 UG  EXAMPLE
            TAMFLG
            SPDFLG
            VMFLAG
            MVMRFG
            NEWFLG
            IMFLAG
            ALHFLG
            ATPFLG
            RLFLAG
            LOCFLG   -
            TEMFLG   -
4           OUTFMT
4           PRTFLG
1            IDLFLG
1            NMHFLG
2           HCFLAG
89 2221        IOBMY,
1  80  19.6 75.0 20.6
SAN FRANCISCO CA C
1  88  19.6 75.0 20.6
SAN FRANCISCO CA C
1  90  19.6 75.0 20.6
SAN FRANCISCO CA C
1  00  19.6 75.0 20.6
SAN FRANCISCO CA C
 4: OUTFMT = 4  (PORTRAIT (80 COLUMN) DESCRIPTIVE  OUTPUT FORMAT)
  READ IN LOCAL  AREA  PARAMETERS AS 2ND REQ  SC  REC
  CALCULATE EXHAUST TEMPERATURES
  PRINT HC COMPONENTS
 IVOB
27.3 20.6
60.  84.  1 1 .5  11 .5  88
27.3 20.6
60.  84.  11.5  11.5  88
27.3 20.6
60.  84.  11.5  11.5  88
27.3 20.6
60.  84.  11.5  11.5  88
   1ST REQ SC REC:  IREJN,ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN,ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN,ICY,
LAP REC: SCNAME,RVPAST.TEMMIN
   1ST REQ SC REC:  IREJN,ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
SPD(1),AMBT.PCCN,PCHC,PCCC
,TEMMAX.RVPBAS.RVPIUS,I USESV
SPD(1).AMBT.PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,IUSESV
SPD(1).AMBT.PCCN,PCHC,PCCC
,TEMMAX,RVPBAS,RVPIUS,I USESY
SPD(1).AMBT.PCCN,PCHC,PCCC
.TEMMAX.RVPBAS.RVPIUS,IUSESY

-------
MOBILE4.1 UG EXAMPLE 4: OUTFMT = 4  (PORTRAIT  (80  COLUMN)  DESCRIPTIVE  OUTPUT  FORM

Total HC emission factors include evaporative  HC  emission factors.
Cal.  Year: 1980
           Region: Low
      I/M Program: No
Anti-tarn. Program: No
      Alt i tude:
  Ambient Temp:
Operating Mode:
                                                            500.  Ft.
                                                             78. 1  /
                                                             20.6  /
78 . 1  / 78. 1
27.3  / 20.6
SAN FRANCISCO CA
                    Minimum Temp: 60.  (F)
                    Period 1 RVP: 11.5
                             Maximum Temp: 84.  (F)
                             Period 2 RVP: 11.5 Period 2 Yr:  1988
Veh. Type LDGV
Veh. Spd.
VMT Mix
Compos i te
Total HC
Exhst HC
Evap. HC
Refuel HC
Runing HC
Rsting HC
Exhst CO
Exhst NOX
Cal . Year
19.6
0.688
Emi ss i on
8.39
4.34
2.44
0.37
1.13
0.12
54.96
3.11
1988
LDGT1
19.6
0. 142
LDGT2
19.6
0.070
Factors (Gm/Mi
9.67
5. 16
2.84
0.43
1.13
0.10
62.89
3.26

16.64 1
7.84
6.06
0.44
2. 20
0. 10
LDGT


le)
1 .98
6.05
3.91
0.44
1 .48
0. 10
82.04 69.23
4.68
Regi on :
3.73
Low
HDGV
19
0

29
14
12
0
2
0
226
7

6
031

67
08
29
61
52
16
27
39

LDDV
19.6
0.005

0.66
0.66




1 .56
1.51
Al t i
LDDT
19.6
0.001

0.99
0.99




2.13
1 .96
tude:
HDDV
19
0

5
5




16
30
500
6
052

48
48




24
06
Ft
MC
19.6
0.01

9.71
6.98
2.29


0.44
33.63
0.47

Al 1

1

9
5
2
0
1
0
60
4

Veh



63
07
91
36
17
1 1
70
74

                      I/M  Program:  No
               Anti-tarn.  Program:  No
                             Ambient Temp:
                           Operating Mode:
                  78. 1  / 78. 1 / 78. 1 F
                  20.6 / 27.3 / 20.6
                                                                                                                                    Ui
                                                                                                                                    I
SAN FRANCISCO CA
                    Minimum  Temp:  60.  (F)
                    Period  1  RVP:  11.5
                             Maximum Temp: 84.  (F)
                             Period 2 RVP: 11.5  Period  2  Yr:  1988
Veh . Type
Veh. Spd.
VMT Mix
Compos i te
Total HC
Exhst HC
Evap. HC
Refuel HC
Runing HC
Rsting HC
Exhst CO
Exhst NOX
Cal . Year
LDGV
19.6
0.639
Emission
4.68
2.27
1 .25
0. 26
0.78
0.12
29.07
1 .70
1990
LDGT1
19.6
0.152
LDGT2
19.6
0.076
Factors (Gm/Mi
6.17
3.38
1 .57
0.33
0.78
0.10
40.56
2.14

8.48
4.18
2.82
0.33
1 .04
0.10
LDGT


le)
6.94
3.65
1 .99
0.33
0.87
0.10
47.98 43.03
2.67
Regi on :
2.32
Low
HDGV
19
0

18
6
8
0
1
0
128
5

6
036

13
95
60
54
89
15
80
96

LDDV
19.6
0.013

0.62
0.62




1 .57
1 .57
Al t i
LDDT
19.6
0.003

0.79
0.79




1 .72
1 .77
tude:
HDDV
19
0

3
3




13
21
500
.6
.072

.40
.40




.95
.52
. Ft
MC
19.
0.

6.
3.
2.


0.
22.
0.


6
009

36
07
85


44
71
80

Al 1 Veh



5.55
2.82
1 .59
0. 26
0.77
0.11
34.31-
3.41

                      I/M  Program:  No
               Anti-tarn.  Program:  No
                             Ambient  Temp:
                           Operating  Mode:
                  78.1 / 78.1 / 78.1 F
                  20.6 / 27.3 / 20.6
SAN FRANCISCO CA
                    Minimum  Temp:  60.  (F)
                    Period  1  RVP:  11.5
                             Maximum  Temp:  84.  (F)
                             Period 2 RVP:  11.5  Period  2  Yr:  -1988

-------
Veh . Type
Veh. Spd.
VMT Mix
Compos
Tota 1
E*hst
Evap .
Ref ue 1
Runi ng
Rst ing
Exhst
Exhst
i te
HC
HC
HC
HC
HC
HC
CO
NOX
LDGV
19
0
6
628
LDGT1
19
0
6
163
LDGT2
19
0
6
077
LDGT


HDGV
19
0
6
037
LDDV
19
0
6
009
LDDT
19
0
6
002
HDDV
19
0
6
076
MC
19
0
6
008
Al 1

Veh

Emission Factors (Gm/Mile)
4
1
1
0
0
0
25
1
09
91
10
22
75
1 1
23
44
5
2
1
0
0
0
34
1
22
87
29
27
68
10
05
89
7
3
2
0
0
0
40
2
14
56
29
28
91
10
33
28
5
3
1
0
0
0
36
2
83
09
61
28
75
10
06
01
15
5
7
0
1
0
105
5
21
67
25
53
62
14
70
78
0
0




1
1
69
69




67
63
0
0




1
1
93
93




90
87
3
3




13
20
03
03




30
07
5
2
2


0
21
0
93
57
91


44
95
82
4
2
1
P
0
0
29
3
82
41
37
22
71
10
62
15
M120 Warning: MOBILE4.1 does not model most  1993  and  later  Clean  Air  Act
              requirements; Emission  Factors  for  CY  1993  or later are affected.
Cal.  Year: 2000
                          Region: Low
                     I/M Program: No
               Anti-tarn. Program: No
      A 11 i tude:
  Ambient Temp:
Operating Mode:
SAN FRANCISCO CA
500.  Ft.
 78. 1  / 78. 1  / 78 . 1  F
 20.6  / 27.3 / 20.6
                    Minimum Temp: 60.  (F)
                    Period 1 RVP; 11.5
  Maximum Temp: 84. (F)
  Period 2 RVP: 11.5 Period 2 Vr:  1988
Veh. Type
Veh. Spd.
VMT Mix
Compos i te
Total HC
Exhst HC
Evap. HC
Refuel HC
Runing HC
Rsting HC
Exhst CO
Exhst NOX
LDGV
19.6
0.589
Emi ss i on
2.74
1 .00
O.B8
0.04
0.73
0.09
15.39
0.78
LDGT1
19.6
0.191
LDGT2
19.6
0.080
Factors (Gm/Mi
3.38
1 .74
0.87
0.07
0.62
0.08
18.91
1 .24
3.73
1 .86
1 .04
0.07
0.68
0.08
LDGT


le)
3.48
1 .77
0.92
0.07
0.64
0.08
21.01 19.53
1 .29
1 .25
HDGV
19
0

9
2
4
0
1
0
44
4
6
038

03
88
46
49
1 1
09
89
66
LDDV
19
0

0
0




1
1
6
002

63
63




60
37
LDDT
19
0

0
0




1
1
6
002

92
92




84
68
HDDV
19
0

2
2




1 1
9
6
092

21
21




39
70
MC
19.
0.

5.
2.
2.


0.
21 .
0.

6
007

48
10
94


44
44
83
A 1 1



3
.1
0
0
0
0
17
1
Veh



14
40
96
06
64
08
24
88
                                                                                                                                       Ul
                                                                                                                                        I

-------

/IOBILE4. 1
1
1






3
1
1

4
1
1
2
39 2221
22222222
PROMPT
UG EXAMPLE 5:
TAMFLG
SPDFLG
VMFLAG
MVMRFG
NEWFLG
IMFLAG
ALHFLG
ATPFLG
RLFLAG
LOCFLG - R
TEMFLG - C
OUTFMT
PRTFLG
IDLFLG
NMHFLG
HCFLAG - P
IOBMV, IV
1 1 B
                         OUTFMT = 5 (= OUTFMT=3  +  BYMY TABLES,  TERSE VERSION)
                       READ IN LOCAL AREA  PARAMETERS AS 2ND REQ SC REC
                       CALCULATE EXHAUST TEMPERATURES
                       PRINT HC COMPONENTS
                       VOB
                       BV MODEL YEAR TABLE  PICKS
1  80 19.6 75.0  20.6  27.3 20.6
SAN FRANCISCO CA  C   60.   84.  11.5 11.5 88
1  88 19.6 75.0  20.6  27.3 20.6
SAN FRANCISCO CA  C   60.   84.  11.5 11.5 88
   1ST REQ SC REC:  I REJN,ICY,SPD(1) ,AMBT,PCCN,PCHC,PCCC
LAP REC: SCNAME,RVPAST,TEMMIN,TEMMAX,RVPBAS,RVPIUS,IUSESY
   1ST REQ SC REC:  IREJN.ICY,SPD(1),AMBT,PCCN,PCHC.PCCC
LAP REC: SCNAME,RVPAST,TEMMIN,TEMMAX,RVPBAS,RVPIUS,IUSESY
                                                                                                                                          Ui
                                                                                                                                           I

-------
MOBILE4.1 UG EXAMPLE 5: OUTFMT = 5 (= OUTFMT=3 + BYMV TABLES, TERSE VERSION)


Total HC emission factors include evaporative HC emission factors.
                                                                                                                                      Ui
                                                                                                                                      I

-------
MOBILE4.1 UG EXAMPLE 5: OUTFMT  =  5  (=  OUTFMT=3 •*- BVMY TABLES, TERSE VERSION)
Cal.  Year:  1980
                        I/M  Program:  No
                 Anti-tarn.  Program:  No
SAN FRANCISCO CA
                       Period  1  RVP:  11.5
  Ambient Temp: 78.1 / 78.1 / 78.1  (F)  Region:  Low
Operating Mode: 20.6 / 27.3 / 20.6   Altitude:   500.  Ft.
  Minimum Temp:  60. (F)
  Period 2 RVP: 11.5
     Maximum Temp:  84. (F)
Period 2 Start Yr: 1988
Veh. Type:
Veh. Speeds:
VMT Mix:
LDGV
19
0
.6
.688
LDGT1
19
0
.6
. 142
LDGT2
19.
0.
.6
.070
LDGT


HDGV
19.
0.
6
.031
LDDV
19
0
.6
.005
LDDT
1 19
0
.6
.001
HDDV
19.
0.
.6
,052
MC
19
0.
.6
.011
A) 1

Veh

Composite Emission Factors (Cm/Mile)
Total
Exhaust
Evaporat
Refuel L
Runing L
Rst ing L
Exhaust
Exhaust
HC:
HC:
HC:
HC:
HC:
HC:
CO:
NOX:
8
4
2
0
1
0
54
3
.39
.34
.44
.37
. 13
. 12
.96
. 1 1
9
5
2
0
1
0
62
3
.67
. 16
.84
.43
. 13
. 10
.89
.26
16.
7,
6.
0,
2.
0.
82
4.
.64
.84
.06
.44
.20
. 10
.04
.68
1 1 .
6.
3.
0.
1 .
0.
69.
3.
.98
.05
.91
,44
.48
. 10
.23
.73
29.
14.
12.
0.
2.
0.
226.
7.
.67
.08
.29
.61
.52
, 16
. 27
.39
0
0




1
1
.66
.66




.56
.51
0
0




2
1
.99
.99




. 13
.96
5.
5.




16.
30.
.48
.48




. 24
.06
9
6
2


0
33
0
.71
.98
. 29


.44
.63
.47
9.
5.
2.
0,
1
0.
60.
4.
,626
.070
.910
.364
. 167
. 1 14
,699
.745
                                                                                                                                        Ul
                                                                                                                                         I

-------
MOBILE4.1 UG EXAMPLE 5:
SAN FRANCISCO CA
OUTFMT = 5 (= OUTFMT=3 + BYMY TABLES, TERSE VERSION)
                                                      Light  Duty Gas Vehicles
                                                          Jan 1, I960
Model
Year TF
1980 .0227
1979 .1107
1978 .1114
1977 . 1045
1976 .1015
1975 .0927
1974 .0832
1973 .0573
1972 .0484
1971 .0468
1970 .0434
1969 .0443
1968 .0365
1967 .0272
1966 .0167
1965 .0125
1964 .0087
1963 .0088
1962 .0061
1961 .0042
1960 .0030
1959 .0024
1958 .0018
1957 .0013
1956 .0040


Miles
1640.
9816.
22403.
34309.
45571 .
56225.
66303.
75837.
84854.
93383.
101452.
109084.
1 16303.
123133.
129593.
135704.
141484.
146951 .
152124.
157016.
161644.
166022.
170162.
174080.
177785.

1
| BEF4
0.461
1 . 445
1 .832
2. 197
2.544
2.871
4.674
4.835
4.987
6.711
6.721
7 . 167
7.348
9.409
9.525
9.635
9.738
9.836
9.929
10.017
10. 100
10. 179
10.253
10.323
10.390

HC |
Tamper SALHCF Evapor Refuel Runnin Restin FER | BEF4
0.043
0.092
0. 208
0.319
0.427
0.516
0.088
0. 105
0.040
0.023
0.024
0.026
0.028
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000 0.643 0.261 0.482 0.086 0.045 / 8.357
.000 0.651 0.301 0.491 0.087 0.340 23.315
.000 0.693 0.306 0.504 0.092 0.405 26.999
.000 1.519 0.330 0.528 0.098 0.522 30.484
.000 1.607 0.347 0.572 0.103 0.568 33.780
.000 1.720 0.384 0.648 0.109 0.579 36.898
.000 1.855 0.424 0.753 0.115 0.658 63.959
.000 2.018 0.424 0.828 0.122 0.478 66.513
.000 2.196 0.417 0.954 0.129 0.422 68.929
.000 3.170 0.420 2.52) 0.136 0.607 79.743
.000 4.627 0.406 2.521 0.144 0.627 76.518
.000 4.765 0.406 2.521 0.152 0.667 83.679
.000 4.906 0.406 2.521 0.161 0.561 85.507
.000 5.801 0.406 2.521 0.170 0.498 106.231
.000 5.947 0.406 2.521 0.180 0.310 107.692
.000 6.097 0.406 2.521 0.190 0.235 109.074
.000 6.250 0.406 2.521 0.201 0.166 10.381
.000 6.406 0.406 2.521 0.213 0.171 11.617
.000 9.865 0.406 2.521 0.225 0.140 12.787
.000 10.030 0.406 2.521 0.237 0.098 13.893
.000 10.198 0.406 2.521 0.251 0.070 • 14.939
.000 10.370 0.406 2.521 0.265 0.056 15.929
.000 10.547 0.406 2.521 0.281 0.043 116.866
.000 10.727 0.406 2.521 0.297 0.031 117.751
.000 10.914 0.406 2.521 0.314 0.098 118.589
2.438 0.368 1.126 0.120 8.394

Tampe r
0.529
1 .007
2.171
3.361
4.552
5.747
2. 137
2.547
0.978
0.547
0.560
0.586
0.632
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000

CO
SALHCF
.000
.000
.000
.000
.000
.000
.000
.000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000

1
FER |
0. 201
2.693
3. 249
3.537
3.890
3.952
5.502
3.959
3.384
3.754
3.346
3.736
3. 145
2.888
1 .796
1 .362
0.961
0.985
0.690
0.480
0.343
0. 273
0. 208
0. 149
0.473
54.957

BEF4
1 .458
1 .776
1 .906
2.029
2.559
2.601
3.045
3.090
4 . 248
4. 248
4.248
4.248
4.248
3.376
3.376
3.376
3.376
3.376
3.377
3. 377
3.377
3.377
3.377
3.377
3.378

NOX
Tamper SALHCF
0. 153
0.221
0.349
0.470
0.579
0.644
0.242
0.225
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0 . 000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
. 000
.000
. 000
.000
.000
.000
.000
.000
.000
.000


FER
0.037
0.221
0. 251
0. 261
0.318
0.301
0. 274
0. 190
0.206
0. 199
0. 184
0. 188
0. 155
0.092
0.056
0.042
0.029
0.030
0.021
0.014
0.010 Ui
0.008 1
0.006 &
0.004
0.013
3.111
                                                      Light  Duty Gas Trucks 1
                                                          Jan 1, 1980
Model
Year TF
1980 .0266
1979 . 1435
1978 . 1338
1977 .1181
1976 . 1 162
1975 .0816
1974 .0646
1973 .0321
1972 .0245
1971 .0245
1970 .0245
1969 .0346
1968 .0302
1967 .0237
1966 .0167
1965 .0095
1964 .0120
1963 .0112
Mi 1 es
1955.
1 1697.
26552.
40409.
53335.
65393.
76642.
87135.
96923.
106054.
1 14572.
122517.
129929.
136843.
143293.
149310.
154922.
160157.
1
I BEF4
0.994
1 .293
2.732
3.142
3.524
3.88 1
4.909
5.097
5. 272
7. 198
7.204
7 .503
7 .689
9.655
9.771
9.879
9.979
10.073
Tamper SALHCF
0.457 1 .000
0.595 1.000
0.750 1 .000
0.935 1 .000
1 . 205
1 . 237
0. 199
0.207
0.071
0.036
0.036
0.037
0.038
0.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.000 1.000
0.000 1.000
0.000 1.000
0.000 1.000
HC | CO
Evapor Refuel Runnin Restin FER | BEF4 Tamper SALHCF
0.566 0.331 0.337 0.065 0.073 14.524 4.360
0.574 0.411 0.337 0.066 0.470 17.284 6.027
0.645 0.396 0.368 0.071 0.664 36.426 7.919
1.647 0.387 0.615 0.076 0.804 40.690 10.159
1.914 0.420 0.835 0.082 0.927 44.664 13.403
2.066 0.442 0.918 0.088 0.704 48.369 13.657
2.231 0.484 1.023 0.094 0.578 67.192 4.804
2.367 0.484 1.032 0.101 0.298 70.115 4.989
2.541 0.476 1.124 0.108 0.235 72.841 1.721
3.609 0.476 2.521 0.116 0.342 84.175 0.882
4.695 0.476 2.521 0.124 0.368 80.771 0.841
4.912 0.476 2.521 0.133 0.539 87.080 0.827
5.138 0.476 2.521 0.143 0.484 88.957 0.847
6.044 0.476 2.521 0.153 0.447 109.332 0.000
6.283 0.476 2.521 0.164 0.322 110.790 0.000
6.531 0.476 2.521 0.176 0.186 112.150 0.000
6.791 0.476 2.521 0.188 0.239 113.419 0.000
7.061 0.476 2.521 0.202 0.227 114.603 0.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
1
FER |
0.501
3.344
5.935
6.008
6.748
5.060
4.653
2.410
1 .826
2.087
1 .997
3.042
2.714
2.592
1 .854
1 .063
1 .357
1 . 279
BEF4
1 .667
1 .721
2.713
2.753
2.791
2.827
3.029
3.068
4. 248
4.248
4. 248
4. 248
4.247
3. 376
3.376
3.377
3.377
3.377
NOX
Tamper SALHCF
0.000
0.000
0.217
0.699
1 .033
1 .036
0.371
0.331
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.000 1 .000
0.000 1.000
0.000 1 .000
FER
0.044
0. 247
0.392
0.408
0. 444
0.315
0. 220
0. 109
0. 104
0. 104
0. 104
0. 147
0. 128
0.080
0.057
0.032
0.040
0.038

-------
1962
1961
1960
1959
1958
1957
1956
.0493 165041.
.0055 169597.
.0039 173847.
.0033 177811.
.0027 181509.
.0019 184959.
.0054 188177.
10. 161
10. 243
10.319
10.390
10.456
10.518
10.576
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000 10.643 0.476 2.521 0.216 1.185 115.708
.000 10.937 0.476 2.521 0.232 0.134 116.738
.000 11.246 0.476 2.521 0.249 0.098 117.699
.000 11.567 0.476 2.521 0.266 0.083 118.595
.000 11.904 0.476 2.521 0.286 0.070 119.431
.000 12.255 0.476 2.521 0.306 0.050 120.211
.000 12.621 0.476 2.521 0.328 0.142 120.939
0.000
0.000
0.000
0.000
0.000
0.000
0.000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
5.709
0.641
0.464
0.392
0.327
0.231
0.649
3.377
3.377
3.377
3.378
3.378
3.378
3.378
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000
.000
.000
.000
.000
.000
.000
0. 167
0.019
0.013
0.011
0.009
0.006
0.018
2.842  0.433   1.131   0.103  9.670
                                                          62.885
                                                                                        3. 257
                                                                                                 Ui

                                                                                                 i—*
                                                                                                 vo

-------
MOBILE4.1 UG EXAMPLE 5: OUTFMT = 5  (= OUTFMT=3 +  BYMY  TABLES,  TERSE  VERSION)
SAN FRANCISCO CA
                                                      Light  Duty  Gas  Trucks  2
                                                          Jan  1,  1980
Mode 1
Year TF
1980 .0221
1979 .1254
1978 .1151
1977 .0888
1976 .0887
1975 .0893
1974 .0788
1973 .0606
1972 .0459
1971 .0358
1970 .0245
1969 .0538
1968 .0431
1967 .0337
1966 .0237
1965 .0140
1964 .0119
1963 .0119
1962 .0079
1961 .0056
1960 .0037
1959 .0038
1958 .0032
1957 .0020
1956 .0067
1
Miles | BEF4
2201 . 1 .002
1 3163 . 1 . 338
29731 . 6.757
44991 . 7.016
59047. 7.254
71992. 7.474
83915. 7.676
94897. 8.664
105012. 8.917
114329. 9.151
122909. 9.366
130812.
138092.
144796.
150970.
156658.
161896.
166721 .
171 165.
175257.
179027.
182499.
185697.
188643.
191355.
1 .853
1 .984
2. 104
2.215
2.317
2.411
2.498
2.577
2.651
2.718
2.781
2.838
2.891
2.940
HC |
Tamper SALHCF Evapor Refuel Runnin Rest in FER | BEF4 Tamper
0.566 1.000 0.529 0.331 0.337 0.058 0.062 ,14.594 5.278
0.747 1.000 0.539 0.410 0.337 0.059 0.430 'l7.699 7.289
0.000 1.000 4.334 0.396 2.521 0.064 1.619 69.823 0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000 4.606 0.386 2.521 0.070 1.296 73.763 0.000
.000 4.890 0.420 2.521 0.076 1.345 77.389 0.000
.000 5.189 0.442 2.521 0.082 1.403 80.728 0.000
.000 5.503 0.484 2.521 0.089 1.282 83.801 0.000
.000 5.833 0.484 2.521 0.097 1.067 83.807 0.000
.000 6.179 0.475 2.521 0.105 0.835 86.367 0.000
.000 6.545 0.475 2.521 0.114 0.674 88.726 0.000
.000 6.917 0.475 2.521 0.124 0.476 90.898 0.000
.000 7.318 0.475 2.521 0.135 1.199 123.717 0.000
.000 7.736 0.475 2.521 0.146 0.984 125.363 0.000
.000 13.754 0.475 2.521 0.159 0.978 126.880 0.000
.000 14.218 0.475 2.521 0.172 0.703 128.276 0.000
.000 14.708 0.475 2.521 0.187 0.423 129.563 0.000
.000 15.225 0.475 2.521 0.203 0.366 130.747 0.000
.000 15.770 0.475 .2.521 0.220 0.374 131.839 0.000
.000 16.346 0.475 2.521 0.239 0.254 132.844 0.000
.000 16.954 0.475 2.521 0.260 0.186 133.770 0.000
.000 17.595 0.475 2.521 0.282 0.125 134.622 0.000
.000 18.272 0.475 2.521 0.306 0.129 135.408 0.000
.000 18.989 0.475 2.521 0.332 0.111 136.131 0.000
0.000 1.000 19.745 0.475 2.521 0.361 0.073 136.797 0.000
0.000 1.000 20.545 0.475 2.521 0.392 0.247 137.411 0.000
CO
SALHCF
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1
FER 1
0.439
3. 134
8.034
6.548
6.864
7.213
6.601
5.082
3.962
3. 179
2.230
6.652
5.398
4. 277
3.046
1.816
1 .553
1 .568
1 .048
0.756
0.500
0.510
0.429
0.278
0.919

BEF4
1 .668
1 .729
4.510
4.568
4.621
4.670
4.715
6.299
6.299
6. 298
6. 298
5.339
5.339
5.339
5.340
5.340
5.340
5.341
5.341
5 . 34 1
5 . 34 1
5.342
5.342
5.342
5.342
NOX
Tamper SALHCF
0.000 1 .000
0.000 1 .000
0.039 1 .000
0.102 .000
0. 123 .000
0. 124 .000
0. 124 .000
0. 127 .000
0.000 .000
0.000 .000
0.000 1 .000
0.000 1 .000
0.000 1 .000
0.000
0.000
0.000
0.000
0.000
0.000
0 . 000
0.000
0.000
0.000
0.000
0.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

FER
0.037
0.217
0.523
0.415
0.421
0.428
0.381
0.390
0.289
0. 226
0. 155
0.287
0.230
0. 180
0. 127
0.075
0.063
0.064
0. 042
0.030
0.020
0.020
0.017
0.011
0.036




















Ul
1
to
0




                                          6.058   0.440   2.199   0.102  16.642
                                                                                                  82.036
                                                                                                                               4.682
                                                      Heavy  Duty  Gas  Vehicles
                                                          Jan  1,  1980
Mode 1
Year
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963

TF
.0000
. 1 188
.1112
.0910
.0868
.0868
.0786
.0572
.0451
.0346
.0282
.0545
.0433
.0356
.0255
.0193
.0161
.0169

Miles
0.
9105.
26595.
42696.
57522.
71171.
83738.
95308.
105961 .
1 15769.
124799.
1331 13.
140768.
147816.
154305.
160279.
165780.
170844.
1
| BEF4
0.000
3.956
7.837
8. 148
9.841
10.769
1 1 .989
13.667
14.089
14.478
14.836
24. 203
24.480
24. 734
24.969
25. 185
25. 384
25.567

Tamper SALHCF Evapor
0.000 0.000 0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.026 1
.026 1
.026 1
.026 1
.026 1
.026 1
.026
.026
.026
.026
.026
.026
.308
.325
.341
.355
.368
.381
.392
.402
.412
.421
.426
.426
.026 16.999
.026 16.999
.026 16.999
0.000 1 .026 16.999
0.000 1.026 16.999
HC
Ref ue 1
0.000
0.562
0.571
0.583
0.598
0.616
0.628
0.641
0.642
0.642
0.642
0.652
0.652
0.652
0.652
0.652
0.652
0.652

Runn i n
0.000
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521
2.521

Rest i n
0.000
0.088
0.096
0. 104
0.113
0. 123
0. 134
0. 145
0. 158
0.171
0. 186
0. 202
0.219
0. 238
0. 259
0. 281
0.305
0.331
I CO I NOX
FER | BEF4 Tamper SALHCF FER | BEF4 Tamper SALHCF
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
2.203 65.898 0.000 1.022 8.003 5.867 0.000 0.996
2.507 146.908 0.000 1.022 16.692 5.181 0.000 0.996
2.084 155.566 0.000 1.022 14.465 5.272 0.000 0.996
2.142 191.032 0.000 1.022 16.939 6.262 0.000 0.996
2.228 210.727 0.000 1.022 18.687 6.741 0.000 0.996
2.120 237.251 0.000 1.022 19.062 7.435 0.000 0.996
1.643 248.591 0.000 1.022 14.534 9.608 0.000 0.996
1.317 256.588 0.000 1.022 11.839 9.608 0.000 0.996
1.025 263.951 0.000 1.022 9.344 9.608 0.000 0.996
0.847 270.730 0.000 1.022 7.815 9.608 0.000 0.996
2.161 318.288 0.000 1.022 17.738 8.983 0.000 0.996
1.727 322.716 0.000 1.022 14.266 8.983 0.000 0.996
1.628 326.793 0.000 1.022 11.876 8.983 0.000 0.996
1.176 330.546 0.000 1.022 8.626 8.983 0.000 0.996
0.893 334.002 0.000 1.022 6.585 8.983 0.000 0.996
0.749 337.184 0.000 1.022 5.546 8.983 0.000 0.996
0.788 340.114 0.000 1.022 5.861 8.983 0.000 0.996

FER
0.000
0.695
0.574
0.478
0.541
0.583
0.582
0.548
0.432
0.332
0.270
0.488
0.387
0.318
0. 229
0. 173
0 . 144
0.151

-------
1962 .0113 175506.
1961 .0078 179799.
1960 .0064 183752.
1959 .0059 187390.
1958 .0037 190741.
1957 .0034 193825.
1956 .0120 196665.
26.323
26.483
26.630
26.765
26.889
27.004
27. 109
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.026 16.999 0.652 2.521 0.360 0.537 350.068 0.000 .022 4.040 9.168 0.000 0.996 0.103
.026 16.999 0.652 2.521 0.391 0.372 352.604 0.000 .022 2.810 9.168 0.000 0.996 0.071
.026 16.999 0.652 2.521 0.425 0.306 354.939 0.000 .022 2.315 9.168 0.000 0.996 0.058
.026 16.999 0.652 2.521 0.461 0.283 357.089 0.000 .022 2.144 9.168 0.000 0.996 0.054
.026 16.999 0.652 2.521 0.501 0.179 359.069 0.000 .022 1.365 9.168 0.000 0.996 0.034
.026 16.999 0.652 2.521 0.544 0.166 360.891 0.000 1.022 1.263 9.168 0.000 0.996 0.031
.026 16.999 0.652 2.521 0.591 0.585 362.569 0.000 1.022 4.460 9.168 0.000 0.996 0.110
12.288  0.615  2.521  0.163  29.666
                                                         226.273
                                                                                        7.387
                                                                                               Ln
                                                                                                I
                                                                                               S3

-------
MOBILE4.1 UG  EXAMPLE 5:  OUTFMT = 5  ( = OUTFMT=3

SAN FRANCISCO CA
BYMY TABLES, TERSE  VERSION)
                                Light Duty  Diesel  Vehicles

                                     Jan  1 ,  1980
Mode 1
Year
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956


TF
. 1804
.4086
.1701
.0863
.0490
.0291
.0384
.0172
.0142
.0067
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000


Mi les
2228.
13327.
30145.
45692.
60063.
73349.
85630.
96984.
107479.
117181.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.



BEF4
0
0
0
0
0
0
1
2
2
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

297
513
631
740
841
934
995
086
169
247
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000


HC
SALHCF
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000



PER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Light
.054
.210
. 107
.064
.041
.027
.077
.036
.031
.015
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.661
Duty
Jan 1 ,
Model
Year
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963

TF
.2118
.5694
.2189
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000
.0000

Mi les
2517.
15025.
33252.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.


BEF4
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
880
980
126
000
000
000
000
000
000
000
000
.000
.000
000
.000
.000
.000
.000

HC

SALHCF
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

FER
. 186
.558
. 246
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000


BEF4
1 .
1 .
1 .
1 .
1 .
1 .
3.
3.
4.
4.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.

159
290
441
581
710
830
822
970
106
232
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000

Diese 1
1980



BEF4
1 .
2.
2.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
995
120
302
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000

CO
SALHCF









1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

1
FER |
0.209
0.527
0.245
0. 136
0.084
0.053
0. 147
0.068
0.058
0.028
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
1 .557

BEF4
.409
.453
.520
.583
.640
.693
.802
1 .847
1 .889
1 .928
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000


NOX
SALHCF
1
t
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000


FER
0. 254
0.594
0.259
0. 137
0.080
0.049
0.069
0.032
0.027
0.013
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
1.514
Trucks



CO
SALHCF
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

I
FER |
0.423
1 . 207
0.504
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000


BEF4
1 .850
1 .950
2 .096
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000



NOX
SALHCF
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000


FER
0.392
1.110
0.459
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
                                                                                                                                          Ul
                                                                                                                                          I
                                                                                                                                          NJ

-------
1962 .0000      0.
1961 .0000      0.
1960 .0000      0.
1959 .0000      0.
1958 .0000      0.
1957 .0000      0.
1956 .0000      0.
0.000
0.000
0.000
0.000
0.000
0.000
0.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.991
0.
0
0
0
0
0
0

.000
.000
.000
.000
.000
.000
.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000

0
0
0
0
0
0
0
2
.000
.000
.000
.000
.000
.000
.000
. 134
0.
0,
0.
0,
0.
0.
0.

.000
.000
.000
.000
.000
.000
.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000
1 .961
                                                                                                                                     Ul

-------
MOBILE4.1 UG EXAMPLE  5:  OUTFMT = 5 (= OUTFMT=3 + BYMY TABLES, TERSE  VERSION)
SAN FRANCISCO CA
                                Heavy Duty Diesel Vehicles
                                     Jan 1,  1980
Mode 1
Year
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956
TF
.0000
. 1650
. 1461
.0979
.0961
. 1072
.0905
.0486
.0396
.0277
.0306
.0315
.0210
.0159
.0063
.0067
.0473
.0077
.0045
.0031
.0019
.0015
.0013
.0005
.0016
Mi les
0.
35671 .
104163.
167179.
225158.
278502.
327582.
372739.
414287 .
452513.
487684.
520044.
549817.
57721 1 .
602415.
625605.
646942.
666573.
684636.
701254.
716545.
730614.
743558 .
755468 .
766426.
HC
BEF4 SALHCF
0
3
4
4
5
5
5
6
6
6
6
6
6
7
7
7
7
7
7
7
7
7
8
8
8
000 0.000
510
545
993
261
581
875
146
396
625
736
900
959
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
123 1.015
154 1.015
294 1.015
422 1.015
539 1.015
648 .015
748 .015
839 .015
924 .015
001 .015
073 .015
139 .015
FER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000
588
674
496
513
607
540
303
257
186
209
221
148
1 15
046
050
356
059
035
024
015
012
01 1
004
013
BEF4
0
14
13
14
15
15
16
17
18
18
18
18
18
19
18
19
19
19
19
20
20
20
20
20
21
000
468
107
325
023
876
661
384
049
660
445
841
937
348
754
078
377
652
905
138
352
549
730
897
050
CO
SALHCF
0.000
1 .021
1 .021
1 .021
1 .021
1 .021
1 .021
1 .021
.021
.021
.021
.021
.021
.021
.021
.021
1 .021
1 .021
1 .021
1 .021
1 .021
1 .021
1 .021
1 .021
1 .021
FER
0
2
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000
437
955
432
474
737
539
863
729
528
576
606
405
314
120
131
936
155
091
064
039
031
028
01 1
034
BEF4
0
23
27
29
29
30
31
32
33
34
34
33
33
34
33
33
33
34
34
34
35
35
35
35
36
.000
.780
.479
. 146
.718
.732
.664
.542
.331
.058
.066
.951
.727
. 220
. 231
.625
.988
.322
.629
.911
.171
.410
.630
.833
.019
NOX
SALHCF
0.000
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
.008
.008
.008
.008
.008
.008
1 .008
1 .008
1 .008
1 .008
1 .008
1 .008
FER
0
3
4
2
2
3
2
1
1
0
1
1
0
0
0
0
1
0
0
0
0
0
0
0
0
000
955
047
876
878
320
888
595
330
951
051
078
713
548
210
228
620
267
157
109
067
052
048
018
058
                                                                                                                                        Ul

                                                                                                                                        N3
                                     5.483
                                                            16.236
                                                                                   30.064


Model
Year TF
1980 .0000
1979 .2568
1978 . 1930
1977 . 1450
1976 . 1083
1975 .0792
1974 .0578
1973 .0420
1972 .0300
1971 .0213
1970 .0146
1969 .0520
1968 .0000
1967 .0000
1966 .0000
1965 .0000
1964 .0000
1963 .0000



Miles
0.
2393.
7023.
1 1343 .
15351 .
19049.
22437 .
25513.
28279.
30735.
32879.
34713.
0.
0.
0.
0.
0.
0.
Mot orcyc 1 es
Jan 1 , 1980
I HC | CO | NOX
| BEF4 SALHCF Evapor Restin FER | BEF4 SALHCF FER | BEF4 SALHCF FER
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
2.750 1.000 2.710 0.336 1.489 25.262 .000 6.488 0.664 .000 0.171
3.419 1.000 2.710 0.359 1.252 26.898 .000 5.190 0.664 .000 0.128
9.562 1.000 1.947 0.386 1.724 37.125 .000 5.382 0.283 .000 0.041
9.860 1.000 1.947 0.418 1.324 38.414 .000 4.160 0.296 .000 0.032
10.135 1.000 1.947 0.454 0.993 39.604 .000 3.137 0.309 .000 0.024
10.386 1.000 1.947 0.498 0.742 40.694 .000 2.353 0.320 .000 0.019
10.615 1.000 1.947 0.551 0.551 41.684 .000 1.750 0.331 .000 0.014
10.821 1.000 1.947 0.616 0.402 42.573 .000 1 . 278 0.340 .000 0.010
11.003 1.000 1.947 0.699 0.291 43.363 .000 0.924 0.348 .000 0.007
11.162 1.000 1.947 0.809 0.203 44.053 .000 0.644 0.355 .000 0.005
11.299 1.000 1.947 0.959 0.738 44.643 .000 2.321 0.361 .000 0.019
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 • 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

-------
1962 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1961 .0000      0.
1960 .0000      0.
1959 .0000      0.
1958 .0000      0.
1957 .0000      0.
1956 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
                                    2.290  0.440  9.709                 33.627                  0.470
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.
0.
0,
0.
0.
.000
.000
.000
.000
.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
                                                                                                                                      Ui

-------
MOBILE4.1 UG EXAMPLE 5: OUTFMT  =  5  (=  OUTFMT=3 + BYMY TABLES, TERSE VERSION)
Cal. Year: 1988         I/M  Program:  No
                 Anti-tarn.  Program:  No
  Ambient Temp: 78.1 / 78.1  /  78.1  (F)  Region:  Low
Operating Mode: 20.6 / 27.3  /  20.6    Altitude:   500.  Ft.
SAN FRANCISCO CA
                       Period  1  RVP:  11.5
                                               Minimum Temp:   60. (F)
                                               Period 2 RVP:  11.5
                                 Maximum  Temp:   84.  (F)
                            Period  2  Start  Yr:  1988
Veh. Type:
Veh. Speeds:
VMT Mix :
LDGV
19.
0.
,6
,639
Composite Emission Factor
Total
Exhaust
Evaporat
Refuel L
Runi ng L
Rst ing L
Exhaust
Exhaust
HC:
HC:
HC:
HC:
HC:
HC:
CO:
NOX:
4 ,
2.
1 ,
0,
0,
0.
29,
1 ,
,68
. 27
.25
. 26
.78
. 12
.07
.70
LDGT1
19.
0,
.6
. 152
LDGT2
19.
0,
.6
.076
LDGT


HDGV
19,
0.
.6
.036
LDDV
19,
0,
.6
.013
LDDT
19.
0.
6
003
HDDV
19
0
.6
.072
MC
19.
0.
.6
.009
Al 1

Veh

-s (Gm/Mile)
6,
3,
1
0,
0
0,
40
2
. 17
.38
.57
.33
.78
. 10
.56
. 14
8
4
2,
0
1
0
47
2
.48
. 18
.82
.33
.04
. 10
.98
.67
6
3
1
0
0
0
43
2
.94
.65
.99
.33
.87
. 10
.03
.32
18,
6.
8,
0,
1 .
0,
128,
5,
. 13
.95
.60
.54
.89
. 15
.80
.96
0
0,




1 ,
1
.62
.62




.57
.57
0.
0.




1 .
1 .
79
79




72
77
3
3




13
21
.40
.40




.95
•52
6,
3,
2,


0,
22,
0.
.36
.07
.85


.44
.71
.80
5,
2,
1 ,
0,
0,
0,
34
3,
.547
.822
.588
.263
.768
. 106
.312
.415
                                                                                                                                       Ul

                                                                                                                                       N5

-------
MOBILE4.1 UG EXAMPLE 5:  OUTFMT  =  5  (=  OUTFMT=3
SAN FRANCISCO CA
BYMY TABLES, TERSE VERSION)
                                                      Light Duty Gas Vehicles
                                                          Jan 1,  1988
Model
Year
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964


TF Mi 1 es
.0240 1640.
. 1 140 9816
. 1 133 22403
. 1052 34309
1011 45571
.0919 56225
.0804 66303.
.0546 75B37
.0469 84854
.0463 93383
.0435 101452
.0446 109084
.0368 116303
.0274 123133
.0168 129593
.0126 135704
.0088 141484
.0089 146951
.0062 152124
.0043 157016
.0030 161644
.0024 166022
.0018 170162
.0013 174080
.0040 177785

1
| BEF4
0.321
0.396
0.510
0.620
0. 750
0.827
1 . 223
1 . 407
1 .475
4.013
4. 261
4.496
4.718
4.927
5.741
5.844
5.941
8. 770
8 .586
8.367
8.483
10. 179
10. 253
10.323
10.390


Tamper SALHCF
0.001
0.007
0.019
0.031
0.041
0. 132
0. 174
0. 231
0.986
0.920
1 .002
1 .039
1 . 144
1 . 186
0. 201
0. 202
0.067
0.033
0.032
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.032 1.000
0.032 1.000
0.000 1.000
0.000 1.000
0.000 1.000
0.000 1.000

HC | CO
Evapor Refuel Runnin Rest in FER | BEF4 Tamper SALHCF
0.422 0.213 0.456 0.068 0.036 4.269 0.015
0.435 0.216 0.456 0.071 0.180 5.691 0.067
0.460 0.218 0.456 0.086 0.198 / 7.837 0.176
0.532 0.225 0.492 0.093 0.210 9.938 0.316
0.575 0.232 0.512 0.102 0.224 12.838 0.418
0.690 0.235 0.589 0.106 0.237 13.939 1.566
0.796 0.235 0.668 0.113 0.258 18.968 2.218
0.951 0.244 0.747 0.122 0.202 22.211 3.134
1.386 0.261 0.954 0.129 0.243 16.514 11.992
1.520 0.301 1.063 0.136 0.368 47.774 9.721
1.781 0.306 1.212 0.144 0.378 50.136 10.626
2.811 -0.330 1.269 0.152 0.450 52.370 11.330
2.911 0.347 1.292 0.161 0.389 54.483 12.867
3.022 0.384 1.309 0.170 0.302 56.482 13.907
3.135 0.424 1.326 0.180 0.185 80.915 4.858
3.228 0.424 1.327 0.190 0.141 82.552 4.876
3.322 0.417 1.327 0.201 0.099 84.100 1.625
4.574 0.420 2.521 0.213 0.147 98.481 0.808
5.816 0.406 2.521 0.225 0.109 92.945 0.749
5.980 0.406 2.521 0.237 0.075 95.814 0.719
6.148 0.406 2.521 0.251 0.054 96.986 0.719
7.070 0.406 2.521 0.265 0.049 115.929 0.000
7.247 0.406 2.521 0.281 0.037 .116.866 0.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
7.427 0.406 2.521 0.297 0.027 117.751 0.000 1.000
7.614 0.406 2.521 0.314 0.086 118.589 0.000 1.000
1.247 0.262 0.784 0.116 4.684
I
FER |
0. 103
0.656
0.908
1 .079
.341
.425
.704
.385
.336
2.663
2.642
2.841
2.478
1 .931
1 .442
1 . 102
0.753
0.885
0.580
0.411
0.295
0.276
0.211
0. 150
0.478
29.070

BEF4
0.465
0.499
0.565
0.832
0.910
0.956
1 .072
1.121
2.021
2.638
2.721
2.800
2.836
2.863
3.346
3.375
4. 248
4 . 248
4 . 248
4. 248
4.248
3.377
3.377
3.377
3.378

NOX
Tamper SALHCF
0.008
0.012
0.020
0.026
0.033
0. 105
0. 124
0. 150
0.825
0.773
0.799
0.825
0.840
0.862
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.316 1 .000
0. 28 1 1 .000
0.000 1 .000
0.000 1 .000
0.000 .000
0.000 .000
0.000 .000
0.000 .000
0.000 .000
0.000 .000
0.000 1 .000


FER
0.011
0.058
0.066
0.090
0.095
0.097
0.096
0.069
0. 133
0. 158
0. 153
0. 162
0. 135
0. 102
0.062
0.046
0.037
0.038
0.026 Y"
0.018 to
0.013 ^J
0.008
0.006
0.004
0.014
1 .700
                                                      Light Duty Gas Trucks  1
                                                          Jan 1,  1988
Model
Year
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
TF
.0278
. 1477
. 1359
. 1 185
.1151
.0788
.0594
.0307
.0240
.0244
.0246
.0351
.0307
.0240
.0170
.0096
.0121
.0113
Mi 1 es
1955.
1 1697.
.26552.
40409.
53335.
65393.
76642.
87135.
96923.
106054.
1 14572.
122517.
129929.
136843.
143293.
149310.
154922.
160157.
BEF4
0
0
0
1
1
2
2
2
3
4
5
5
5
5
6
6
6
9
603
774
922
048
795
173
373
559
908
188
333
568
787
991
102
210
310
278
Tamper
0.
0.
0.
0.
0.
0.
0.
0.
1 .
2.
2.
2.
2 .
2.
0.
0.
0.
0.
010
033
084
120
174
693
814
897
907
049
022
1.40
409
125
238
238
079
039
SALHCF
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
HC
Evapor Refuel
0.339
0
0
0
0
0
0
1
1
1
2
3
3
3
3
3
3
5
383
445
525
599
772
898
045
753
957
093
139
337
484
637
797
965
524
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
288
280
283
295
297
292
302
308
331
41 1
396
387
420
442
484
484
476
476
Runnin
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
2
337
340
348
375
413
546
651
725
124
266
300
313
369
369
369
369
369
521
Rest in
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
056
058
068
077
080
088
097
101
108
1 16
124
133
143
153
164
176
188
202
1
FER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
045
276
292
289
387
360
305
173
219
244
277
445
413
326
204
1 18
150
204
BEF4
2
8
12
15
23
30
32
34
41
44
63
65
68
70
85
87
88
103
771
243
528
570
501
105
382
506
430
016
464
902
176
296
759
435
998
100
CO
Tamper SALHCF
0
0
0
1
2
8
9
10
20
21
20
21
24
21
5
5
1
0
.084
.312
.968
.451
. 155
. 129
.889
.871
.115
.395
.681
.785
.540
.851
.746
.746
.915
.952
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
I
FER |
0
1
1
2
2
3
2
1
1
1
2
3
2
2
1
0
1
1
080
264
833
017
954
014
513
394
475
598
071
078
842
216
553
896
103
178
BEF4
0
0






2
2
2
2
3
3
3
3
4
4
.795
.916
.077
. 181
.429
.761
.791
.820
.191
.241
.971
.994
.016
.036
.281
.304
.'247
. 247
NOX
Tamper SALHCF
0
0
0
0
0
0
0
0
1
1
1
1
1
1
0
0
0
0
005
027
050
071
099
444
495
545
17 1
174
048
050
052
052
376
334
000
000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
FER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
022
139
153
148
176
174
136
073
081
083
099
142
125
098
062
035
052
048

-------
1970 .0500 165041 .
1969 .0056 169597.
1968 .0040 173847.
1967 .0034 17781 1 .
1966 .0028 181509.
1965 .0019 184959.
1964 .0054 188177.
9.061
8.682
8.788
10. 390
10.456
10.518
10.576
0.038
0.038
0.038
0.000
0.000
0.000
0.000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
6.664
6.959
7.267
8 .267
8 .604
8 .955
9.321
0.476
0.476
0.476
0.476
0.476
0.476
0.476
2.521
2.521
2.521
2.521
2.521
2.521
2.521
0.216
0.232
0.249
0.266
0.286
0.306
0.328
0.949
0. 105
0.077
0.074
0.062
0.044
0. 126
97 . 132
99.000
100.076
1 18.595
119. 431
120. 21 1
120.939
0.882
0.847
0.847
0.000
0.000
0.000
0.000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
4.904
0.556
0.403
0.398
0.332
0.234
0.658
4. 247
4.247
4.246
3.378
3.378
3.378
3.378
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.000
.000
.000
.000
.000
.000
.000
0.212
0.024
0.017
0.011
0.009
0.007
0.018
1.571  0.331  0.780   0.101  6.166
                                                          40.562
                                                                                         2. 145
                                                                                                 t_n
                                                                                                 I
                                                                                                 t-o
                                                                                                 OO

-------
MOBILE4.1 UG EXAMPLE 5:
SAN FRANCISCO CA
                        OUTFMT  =  5  (=  OUTFMT=3  +  BVMY  TABLES,  TERSE VERSION)
                                                      Light  Duty  Gas Trucks 2
                                                          Jan 1 ,  1988
Model
Year
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964


TF
.0233
. 1296
. 1 172
.0894
.0882
.0867
.0727
.0583
.0451
.0358
.0248
.0547
.0438
.0343
.0242
.0143
.0121
.0121
.0080
.0058
.0038
.0038
.0032
.0021
.0068


Mi les
2201 .
13163.
29731 .
44991 .
59047.
71992.
83915
94897
105012
1 14329
122909
130812
138092
144796
150970
156658
161896
166721
171 165
175257
179027
182499
185697
188643
191355

I

| BEF4
0
0
0
1
1
2
2
2
4
4
8
8
8
8
8
10
10
10
10
1 2
12
12
12
12
12

606
789
948
076
896
290
502
697
156
442
337
471
594
707
812
21 1
342
463
574
651
718
781
838
891
940


Tarn
0.
0.
0.
0.
0.
0.
0.
0.
2.
2.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.


per
01 1
038
093
133
209
775
907
978
446
623
000
000
000
000
000
000
000
000
000
000
000
000
000
000
000


SALHCF
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000
1 .000


Eva
0.
0.
0.
0.
0.
0.
0.
1 .
1 .
2.
6.
7.
7.
8.
8.
9.
9.
10.
10.
1 1 .
12.
18.
18.
19.
20.
2.

por
302
342
404
481
565
749
884
023
856
096
929
333
752
195
661
153
674
221
767
376
016
272
989
745
545
823
HC

Refuel
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.289
.281
.284
.295
.298
.294
.304
.309
.331
.410
.396
.386
.420
.442
.484
.484
.475
.475
.475
.475
.475
.475
.475
.475
.475
.335


Runni n
0
0
0
0
0
0
0
0
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
.337
.341
.350
.375
.423
.569
.679
.740
. 154
.296
.521
.521
.521
.521
.521
.521
.521
.521
.521
.521
.521
.521
.521
.521
.521
.044



Rest in
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.050
.052
.061
.070
.074
.083
.092
.097
. 105
.114
. 124
. 135
. 146
. 159
. 172
. 187
.203
. 220
.239
.260
. 282
.306
.332
.361
.392
.101
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
8
1
FER |
.037
. 239
.251
.217
.306
.413
.390
.341
.453
.393
.454
.031
.852
.687
.499
.322
. 281
.289
. 197
. 157
. 106
. 132
.113
.074
.251
.484


BEF4
2
8
12
'16
24
31
33
36
43
46
93
95
97
99
101
99
100
101
103
133
134
135
136
'136
137

817
502
948
036
657
441
855
078
721
361
845
879
753
478
068
442
768
989
1 14
770
622
408
131
797
41 1


Tarn
0.
0.
1 .
1 .
2.
9.
1 1 .
12.
24.
25.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.

CO
per SALHCF
097 1 .000
387 1 .000
083 1 .000
618 1 .000
575 1 .000
343 1 .000
283 1 .000
024 1 . 000
252 1 .000
814 1 .000
000 1 .000
000 1 .000
000 1 .000
000 1 .000
000
000
000
000
000
000
000
000
000
000
000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000



0
1
1
1
2
3
3
2
3
2
2
5
4
3
2
1
1
1
0
0
0
0
0
0
0
47
1
FER |
.068
. 152
.645
.578
.402
.535
. 282
.803
.063
.585
.325
. 248
.285
.414
.443
.419
.218
.235
.828
.769
.509
.519
.437
.283
.935
.979


BEF4
0
0
1
1
1
1
1
1
2
2
4
4
4
4
4
6
6
6
6
5
5
5
5
5
5

796
922
092
291
467
779
81 1
841
236
287
862
892
920
945
969
297
297
297
296
341
341
342
342
342
342


Tarn
0.
0.
0.
0.
0.
0.
0.
0.
1 .
1..
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.

NOX


per SALHCF
004
029
057
079
121
472
530
583
173
176
125
125
125
125
125
128
000
000
000
000
000
000
000
000
000

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2

FER
.019
. 123
. 135
. 122
. 140
. 195
. 170
.141
. 154
. 124
. 124
.275
.221
. 174
. 1 23
.092
.076
.076
.051
.031
.020
.020
.017
.011
.036
.670
                                                      Heavy Duty Gas Vehicles
                                                          Jan 1, 1988
Model
Year
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
TF
.0000
. 1 188
.1112
.0910
.0868
.0868
.0786
.0572
.0451
.0346
.0282
.0545
.0433
.0356
.0255
.0193
.0161
.0169
Mi les
0.
9105.
26595.
42696.
57522.
71171.
83738.
95308.
105961 .
1 15769.
124799.
1331 13.
140768.
147816.
154305.
160279.
165780.
170844.
I
| BEF4
0
1
2
2
4
4
4
4
5
5
9
9
1 1
12
13
16
16
16
000
004
373
774
455
549
756
947
418
937
735
895
704
640
855
242
460
661
Tamper
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000
180
046
058
068
078
090
000
000
000
000
000
000
000
000
000
000
000
SALHCF
0.000
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
HC
Evapor Refuel
0.000
1 .866
1 .997
3.071
1 1 .353
1 1 .366
1 1 .378
1 1 .389
1 1 .402
11.412
1 1 .421
1 1 .426
1 1 .426
1 1 .426
1 1 .426
1 1 .426
1 1 .426
1 1 .426
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000
494
495
504
499
500
503
520
530
562
571
583
598
616
628
641
642
642
Runni n
0
0
0
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
000
456
486
762
521
521
521
521
521
521
521
521
521
521
521
521
521
521
Rest in
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.000
.042
.045
.049
.113
. 123
. 134
. 145
. 158
.171
. 186
.202
.219
. 238
.259
.281
.305
.331
FER
0
0
0
0
1
1
1
1
0
0
0
1
1
0
0
0
0
0
000
484
612
663
659
671
534
124
91 1
719
697
357
158
987
742
608
512
540
BEF4
0
16
43
56
81
87
92
98
108
120
199
204
243
261
287
297
301
305
000
693
317
050
766
055
800
091
747
606
717
188
334
607
974
365
495
296
CO
Tamper SALHCF
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000 0.000
104 1.022
529
667
625
734
842
000
000
.022
.022
.022
.022
.022
.022
.022
000 1 .022
000 1 .022
000 1 .022
000 .022
000 .022
000 .022
000 .022
000 .022
000 .022
1
FER |
0
2
4
5
7
7
7
5
5
4
5
1 1
10
9
7
5
4
5
000
283
982
274
306
785
524
735
017
269
765
379
757
507
515
863
959
261
BEF4
0
4
4
4
5
5
5
5
6
6
5
5
6
7
8
9
9
9
000
800
839
892
207
526
587
644
083
492
738
785
813
321
036
608
608
608
NOX
Tamper SALHCF
0
0
0
0
0
0
0
0
0
' 0
0
0
0
0
0
0
0
0
000
016
083
282
000
000
000
000
000
000
000
000
000
000
000
000
000
000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000
996
996
996
996
996
996
996
996
996
996
996
996
996
996
996
996
996
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
FER
.000
.570
.545
.469
.450
.478
.438
.322
.274
. 224
. 161
.314
. 294
. 259
. 204
. 185
. 154
. 161

-------
1970
1969
1968
1967
1966
1965
1964
.0113 175506.
.0078 179799.
.0064 183752.
.0059 187390.
.0037 190741 .
.0034 193825.
.0120 196665.
16.846
25.891
26.033
26. 165
26. 286
26.398
26.500
0.000
0.000
0.000
0.000
0.000
0.000
0.000
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 .026
1 1 .426
1 1 .426
1 1 .426
16.999
16.999
16.999
16.999
0.642
0.652
0.652
0.652
0.652
0.652
0.652
2.521
2.521
2.521
2.521
2.521
2.521
2.521
0.360
0.391
0.425
0.461
0.501
0.544
0.591
0.364 308.796
0.324 345.294
0.266 347.580
0.279 349.685
0. 177 351 .623
0. 164 353.408
0.577 355.050
0.000
0.000
0.000
0.000
0.000
0.000
0.000
.022
.022
.022
.022
.022
.022
.022
3.563
2.752
2.267
2. 100
1 .336
1 . 236
4.368
9.608
8.983
8.983
8.983
B.9B3
8.983
8.983
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.996
0.996
0.996
0.996
0.996
0.996
0.996
0. 108
0.070
0.057
0.053
0.033
0.031
0. 108
8.602  0.537  1.890  0.147  18.129
                                                        128 .803
                                                                                      5.963
                                                                                              U>
                                                                                              O

-------
MOBILE4.1 UG EXAMPLE  5:  OUTFMT = 5 ( = OUTFMT=3 + BYMY TABLES, TERSE  VERSION)
SAN FRANCISCO CA
                                Light Duty Diesel Vehicles
                                     Jan 1,  1988
Model
Vear
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964

TF
.0000
.0230
.0224
.0612
. 1095
. 1206
. 2372
. 2002
. 1232
.0555
.0215
.0119
.0058
.0028
.0025
.0012
.0008
.0004
.0000
.0000
.0000
.0000
.0000
.0000
.0000

Mi les
0.
13327.
30145.
45692.
60063.
73349.
85630.
96984.
107479.
117181.
126150.
134440.
142104.
149189.
155739.
161793.
167390.
172564.
0.
0.
0.
0.
0.
0.
0.

BEF4
0
0
0
0
0
0
0
0
0
1
1
1
1
1
2
2
2
2
0
0
0
0
0
0
0

000
330
380
427
470
510
547
581
613
240
303
361
415
464
555
604
649
690
000
000
000
000
000
000
000

HC
SALHCF
0
1
1
1
1
1
1
1
i
i







i
0
0
0
0
0
0
0

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

1
FER |
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
000
008
009
026
052
062
130
1 16
075
069
028
016
008
004
006
003
002
001
000
000
000
000
000
000
000
615
CO
BEF4 SALHCF
0








2
2
2
2
2
4
4
4
4
0
0
0
0
0
0
0

000 0.000
203
271
333
390
443
492
538
580
224
305
379
448
512
733
812
885
952
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
000 0.000
000 0.000
000 0.000
000 0.000
000 0.000
000 0.000
000 0.000

I
FER |
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
000
028
028
082
152
174
354
308
195
123
050
028
014
007
012
006
004
002
000
000
000
000
000
000
000
567
BEF4
0
0
0
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
0
0
0
0
0
0
0

000
910
961
007
491
5.31
568
602
831
868
904
937
968
996
082
106
129
149
000
000
000
000
000
000
000

NOX
SALHCF
0








1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

FER
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
000
021
021
062
163
185
372
321
226
104
041
023
01 1
006
005
003
002
001
000
000
000
000
000
000
000
565
                                                                                                                                         Ln
                                 Light Duty Diesel Trucks
                                     Jan  1, 1988
Model
Year
1988
1987
1986
1985
1984
1983
1982
1981
19BO
1979
1978
1977
1976
1975
1974
1973
1972
1971

TF
.0038
.0295
.0595
.0772
. 1506
.2064
.3110
.0899
.0418
.021 1
.0092
.0000
.0000
.0000
.0000
.0000
.0000
.0000
1
Miles |
2517.
15025.
33252.
49230.
63326.
75843.
87030.
97091 .
106200.
1 14500.
1221 12.
0.
0.
0.
0.
0.
0.
0.

HC
BEF4 SALHCF
0.440
0.490
0.563
0.627
0.683
0.733
0.778
0.819
1.710
1 .776
1 .837
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000' 0.000
0.000 0.000
0.000 0.000
0.000 0.000
I

FER | BEF4
0.002
0.014
0.033
0.048
0. 103
0.151
0.242
0.074
.340
.390
.463
.527
.583
.633
.678
.718
0.071 3.032
0.037 3.115
0.017 3 . 190
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
CO
SALHCF
.000
.000
.000
.000
.000
.000
1 .000
1 .000
1 .000
1 .000
1 .000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
1
FER |
0.005
0.041
0.087
0.118
0.238
0.337
0.522
0. 155
0. 127
0.066
0.029
0.000
0.000
0.000
0.000
0.000
0.000
0.000
NOX
BEF4 SALHCF
1 .078
1 .525
1 .580
1 .628
1 .670
1 .707
1 .741
1.771
2.679
2.745
2.807
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000

FER
0.004
0.045
0.094
0. 126
0. 252
0.352
0.541
0. 159
0.112
0.058
0.026
0.000
0.000
0.000
0.000
0.000
0.000
0.000

-------
1970 .0000      0.
1969 .0000      0.
1968 .0000      0.
1967 .0000      0.
1966 .0000      0.
1965 .0000      0.
1964 .0000      0.
0.000
0.000
0.000
0.000
0.000
0.000
0.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000

0
0.
0
0
0
0
0
0
.000
.000
.000
.000
.000
.000
.000
.794
0.
0.
0.
0.
0.
0.
0.

.000
,000
.000
.000
.000
.000
.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000
1 .725
0.
0.
0.
0.
0.
0,
0.

,000
.000
.000
,000
.000
.000
.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000

0.000
0.000
0.000
0.000
0.000
0.000
0.000
1 .769
                                                                                                                                       Ol
                                                                                                                                        I
                                                                                                                                       to

-------
MOBILE4.1 UG EXAMPLE  5:  OUTFMT = 5 ( = OUTFMT=3 + BYMY TABLES, TERSE VERSION)

SAN FRANCISCO CA
                                Heavy Duty Diesel Vehicles

                                     Jan 1 ,  1988
Model
Year
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964

TF
.0000
. 1652
. 1462
.0979
.0961
. 1072
.0905
.0486
.0396
.0277
.0306
.0315
.0209
.0159
.0063
.0067
.0472
.0077
.0045
.0031
.0019
.0015
.0013
.0005
.0016
1
Mi 1 es |
0.
28495.
83199.
133514.
179795.
222364.
261521 .
297538.
330670.
361 147.
389182.
414971 .
438695.
460519.
480596.
499065.
516057.
531688.
546069.
559298.
571470.
582668.
592970.
602448.
61 1 168.
HC
BEF4 SALHCF
0.000 0.000
2.230 1.015
2. 280 1.015
2.590 1.015
2.820 1.015
2.660 1.015
2.780
3. 170
3. 170
3.510
6. 255
6.480
6.542
6.673
6.794
6.904
7.006
7. 100
7.086
7. 136
7.089
7. 156
7 . 098
7. 155
7. 207
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
.015
I
PER |
0.000
0.374
0.338
0. 258
0.275
0. 289
0. 255
0. 156
0. 127
0.099
0. 194
0.207
0. 139
0. 107
0.043
0.047
0.336
0 .056
0.032
0.022
0.014
0.011
0.010
0.004
0.012
CO
BEF4 SALHCF
0.000 0.000
10.396
1 1 . 109
1 1 .552
13.058
12.661
13.735
15.943
16.307
18.374
17 .667
18.290
18.439
.021
.021
.021
.021
.021
.021
.021
.021
.021
.021
.021
.021
18.788 1.021
19.110 1 .021
19.405 1 .021
19.677 1 .021
19.927 1 .021
19.321 1 .021
19.429 1 .021
19. 262 1 .021
19.430 1.021
18.622 1 .021
18.754 1 .021
18.876 1 .021
1
FER |
0.000
.753
.659
. 155
.281
.386
.269
0.791
0.659
0.519
0.551
0.588
0.394
0.304
0.122
0. 133
0.948
0. 157
0.088
0.061
0.037
0.029
0.025
0.009
0.031
NOX
BEF4 SALHCF
0.000 0.000
17. 180
17.560
17.530
19.080 i
18.060
18.840
21 .470
21 .470
23.780
32.894
33.854
33.775
34. 190
34.571
34.942
35. 265
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
.008
35.562 1 .008
35. 175 1 .008
34.657 1.008
34. 1 16 1 .008
34.318 1.008
33.070 1.008
33.232 1.008
33.380 1.008

FER
0.000
2.860
2. 589
1.731
1 .848
1 .951
1.718
1 .052
0.856
0.664
1.013
1 .074
0.713
0.547
0.218
0.236
1 .678
0.276
0. 159
0. 108
0.065
0.050
0.045
0.016
0.053
                                                                                                                                        I
                                                                                                                                        u>
                                                                                                                                        u>
                                     3.405
                                                            13.951
                                                                                   21.520
Motorcyc 1 es

Model
Year TF
1988 .0000
1987 .2568
1986 . 1930
1985 .1450
1984 .1083
1983 .0792
1982 .0578
1981 .0420
1980 .0300
1979 .0213
1978 .0146
1977 .0520
1976 .0000
1975 .0000
1974 .0000
1973 .0000
1972 .0000
1971 .0000


Mi 1 es
0.
2393.
7023.
1 1343.
15351 .
19049.
22437.
25513.
28279.
30735.
32879.
34713.
0.
0.
0.
0.
0.
0.

I
| BEF4 SALHCF
0.000 0.000
1 .484
1 .830
2. 153
3.098
3.448
3. 769
4.849
5. 166
6.841
7.151
1 1 . 299
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000

HC
Evapor
0.000
2.940
2.940
2.940
2.853
2.853
2.853
2 .865
2.865
2.710
2.710
1 .947
0.000
0.000
0.000
0.000
0.000
0.000
Jan 1

Rest in
0.000
0.336
0.359
0.386
0.418
0.454
0.498
0.551
0.616
0.699
0.809
0.959
0.000
0.000
0.000
0.000
0.000
0.000
, 1988

FER
0.000
1 . 223
0.990
0.794
0.690
0.535
0.412
0.347
0.260
0.218
0. 156
0.738
0.000
0.000
0.000
0.000
0.000
0.000

CO
BEF4 SALHCF
0.000 0.000
18.751 1.000
19.930
21 .029
22.050
22.991
23.854
24.937
25.662
35. 275
36.033
44.643
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000

1
FER |
0.000
4.816
3.846
3.049
2:388
1 .821
1 .379
1 .047
0.770
0.752
0.527
2.321
0.000
0.000
0.000
0.000
0.000
0.000

NOX
BEF4 SALHCF
0.000 0.000
0.830 1 .000
0.830 1.000
0.830 .000
0.830 .000
0.830 .000
0.830 .000
0.830 .000
0.830 .000
0.664 .000
0.664 .000
0.361 .000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000
0.000 0.000


FER
0.000
0.213
0. 160
0. 120
0.090
0.066
0.048
0.035
0.025
0.014
0.010
0.019
0.000
0.000
0.000
0.000
0.000
0.000

-------
1970 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1969 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1968 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1967 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1966 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1965 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
1964 .0000      0.     0.000  0.000  0.000  0.000  0.000    0.000  0.000  0.000    0.000  0.000  0.000
                                    2.854  0.440  6.363                 22.715                  0.800
                                                                                                                                      Ln
                                                                                                                                       I
                                                                                                                                      Co

-------
                              5-35


     5.1.2  User-Supplied Registration Distributions
            and Annual Mileage Accumulation Rates by Age

     Example 6  illustrates  the use  of  the options  for  supplying
alternate   registration   distributions    and    annual    mileage
accumulation rates.   In  the  example,  the  registration  fractions
for  vehicles  of  ages 21  to  25+ have  been set  to zero.   This
necessitates the zero mileage accumulation rates for vehicles  of
these ages  (since vehicles  of a given age that  exist in the fleet
must accumulate mileage).   The same  calendar years  as  in examples
1 through  5 are modeled  (1980,  1988, 1990, and 2000).   The only
other difference between the first five examples and this example
is   that   refueling  HC  emission   factors are  not  calculated
(RLFLAG=5).  The 112-column descriptive output  is used (OUTFMT=3).

     Note the warning messages  that  precede the emission factors
in the output.  The message M 49 is frequently generated when the
sum of the registration fractions for a given vehicle type is not
exactly  1.000;  even  if  the values  entered do  add  to  1.000,  the
representation  of   decimal  numbers  in the computer  will  often
result in  round-off errors large enough  to trigger this message.
A user  entering registration distributions by  age  as  input data
and  finding this  message in  the output  should  recheck  the input
data for errors; if none are found,   then it can be assumed that
the  message was generated due  to internal  representation of the
input values as described above.
                                                                07/91

-------
1
MOBILE4
1
1
1
4
1
1
1
1
5
1
1
3
4
1
1
1
. 12800
.07200
0.0
. 17400
.08200
0.0
. 18400
.08300
0.0
. 19900
.07400
0.0
. 12800
.07200
0.0
. 17500
.08200
0.0
. 19900
.07400
0.0
.04100
.00200
0.0
.075 .
.039 .
0.0
.061 .
.036 .
0.0
.037 .
.044 .
0.0
.037 .
.044 .
0.0
.075 .
.039 .
0.0
.061 .
.036 .
0.0
PROMPT
. 1 UG EXAMPLE 6: MVMRFG = 4 (NEW MILEAGE ACCRUAL RATES & REGISTRATION DISTRIBU.)
TAMFLG
SPDFLG
VMFLAG
MYMRFG
NEWFLG
IMFLAG
ALHFLG
ATPFLG
RLFLAG
LOCFLG - READ IN LOCAL AREA PARAMETERS AS 2ND REQ SC REC
TEMFLG - CALCULATE EXHAUST TEMPERATURES
OUTFMT
PRTFLG
IDLFLG
NMHFLG
HCFLAG -
. 12100
.06800
0.0
.16100
.07600
0.0
. 16900
.07600
0.0
.18100
.06700
0.0
.12100
.06800
0.0
. 16300
.07600
0.0
.18100
.06700
0.0
.02800
.00000
0.0
107 .107
027 .018
0.0
095 .094
024 .030
0.0
070 .078
032 .038
0.0
070 .078
032 .038
0.0
107 .107
027 .018
0.0
095 .094
024 .030
0.0
. 1 1400
.06400
0.0
. 15000
.07000
0.0
. 15600
.07100
0.0
. 16400
.06100
0.0
. 1 1400
.06400
0.0
.15100
.07000
0.0
. 16400
.06100
0.0
.02100
.00000
0.0
.106
.014
0.0
.103 .
.028
0.0
.086
.036
0.0
.086 .
.036
0.0
.106
.014
0.0
'.103 ,
.028
0.0
DO NOT PRINT HC COMPONENTS
. 10800 . 10200
.06100 .05700
0.0 0.0
. 13900 . 12900
.06500 .06100
0.0 0.0
. 14400 . 13300
.06500 .06000
0.0 0.0
. 14800 . 13400
.05500 .05000
0.0 0.0
. 10BOO . 10200
.06100 .05700
0.0 0.0
. 14000 . 12900
.06500 .06000
0.0 0.0
. 14800 . 13400
.05500 .05000
0.0 0.0
.01600 .01200
.00000 .00000
0.0 0.0
.100 .092 .085
.009 .006 .005
0.0 0.0
.083 .076 .076
.026 .024 .022
0.0 0.0
.075 .075 .075
.034 .032 .030
0.0 0.0
.075 .075 .075
.034 .032 .030
0.0 0.0
. 100 .092 .085
.009 .006 .005
0.0 0.0
.083 .076 .076
.026 .024 .022
0.0 0.0
.09600
.05400

. 1 1900
.05600

. 12300
.05600

.12100
.04500

.09600
.05400

. 12000
.05600

.12100
.04500

.00800
.00000

.077 .
.005 .

.063 .
.020 .

.068 .
.028 .

.068 .
.028 .

.077 .
.005 .

.063 .
.020 .

.09100
.05100

. 1 1 100
.05200

. 1 1400
.05100

. 1 1000
.04100

.09100
.05100

. 1 1 100
.05200

. 1 1000
.04100

.00600
.00000

066 .052
005 .004

054 .043
018 .016

059 .053
026 .024

059 .053
026 .024

066 .052
005 .004

054 .043
018 .016

.08600
.04800

. 10300
.04800

. 10500
.04700

. 10000
.03700

.08600
.04800

. 10300
.04800

. 10000
.03700

.00400
.00000



















.08100
.04600

.09500
.04500

.09700
.04400

.09000
.03300

.08100
.04600

.09500
. 04400

.09000
.03300

.00200
.00000



















.07600
.04300

.08800
.04200

.09000
.04000

.08200
.03000

.07600
.04300

.08800
.04100

.08200
.03000

.00200
.00000

JULMYR

















AMAR























. LDGV.
. LDGV.
. LDGV.
. LDGT1
. LDGT1
. LDGT1
. LDGT2
. LDGT2
. LDGT2
. HDGV.
. HDGV. .
.HDGV . .
. LDDV. .
. LDDV. ,
. LDDV. ,
. LDDT. ,
. LDDT. ,
. LDDT. .
. LDGV. .MY AGES
. LDGV. .MY AGES
. LDGV. .MY AGES
. LDGT1 .MY AGES
. LDGT1 .MY AGES
. LDGT1 .MY AGES
. LDGT2.MY AGES
.LDGT2.MY AGES
.LDGT2.MY AGES
.HDGV. .MY AGES
.HDGV. .MY AGES
.HDGV. .MY AGES
.LDDV. .MY AGES
. LDDV. .MY AGES
. LDDV. .MY AGES
.LDDT. .MY AGES
.LDDT. .MY AGES
.LDDT. .MY AGES
. HDDV. .MY AGES
.HDDV. .MY AGES
.HDDV. .MY AGES
.MC. . . .MY AGES
.MC. . . .MY AGES
.MC. . . .MY AGES
.MY AGES 1-10
.MY AGES 1 1-20
.MY AGES 21-25
.MY AGES 1-10
.MY AGES 1 1-20
.MY AGES 21-25
.MY AGES 1-10
.MY AGES 1 1-20
.MY AGES 21-25
.MY AGES 1-10
.MY AGES 1 1-20
.MY AGES 21-25
.MY AGES 1-10
.MY AGES 1 1-20
.MY AGES 21-25
.MY AGES 1-10
.MY AGES 1 1-20
.MY AGES 21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25
1-10
1 1-20
21-25


















Ul
 I
u>

-------
 .077 .135 .134 .131
 .025 .015 .013 .011
 0.0    0.0    0.0
 . 105 .225 .206 . 149
 .008 .005 .013 .000
 0.0    0.0    0.0
1  80 19.6 75.0 20.6
SAN FRANCISCO CA C
1  88 19.6 75.0 20.6
SAN FRANCISCO CA C
1  90 19.6 75.0 20.6
SAN FRANCISCO CA C
1  00 19.6 75.0 20.6






27
60
27
60
27
60
27
60
099
010
0.0
097
000
0.0
.3

.3

.3

.3







20
84
20
84
20
84
20
84
090
008
0
062
000
0
.6
. 1
.6
. 1
.6
. i
.6
. 1
.082
.007
.0
.046
.000
.0

1.5 11

1.511

1.511

1.5 11
.062 ,
.006 .

.033 ,
.000 .


.5 88

.5 88

.5 88

.5 88
.045
.005

.029
.000









.033
.004

.023
.000


LAP

LAP

LAP

LAP






1ST I
REC
1ST I
REC
1ST I
REC
1ST
REC
                 .HDDV..MY AGES  1-10
                 .HDDV..MY AGES  11-20
                 .HDDV..MY AGES  21-25
                 .MC....MY AGES  1-10
                 .MC....MY AGES  11-20
                 .MC....MY AGES  21-25
REQ SC REC: I REJN,ICY,SPD(1) ,AMBT,PCCN,PCHC,PCCC
  SCNAME,RVPAST,TEMMIN,TEMMAX,RVPBAS,RVPIUS.IUSESY
REQ SC REC: IREJN,ICY
-------
MOBILE4.1 UG EXAMPLE 6: MYMRFG = 4  (NEW MILEAGE  ACCRUAL  RATES  8.  REGISTRATION DIS










M 49 Warning:  0.999     MVR sum not  =  1.  (will  normalize)






M 49 Warning:  0.992     MYR sum not  =  1.  (will  normalize)






M 49 Warning:  0.999     MYR sum not  =  1.  (will  normalize)






M 49 Warning:  0.992     MYR sum not  =  1.  (will  normalize)






M 49 Warning:  0.992     MYR sum not  =  1.  (will  normalize)






M 49 Warning:    1.00     MYR sum not  =  1.  (will  normalize)






M 21 Warning:  0.500E-02 registration with  zero  mileage






M 21 Warning:  0.130E-01 registration with  zero  mileage




Total HC emission factors  include evaporative  HC emission  factors.
u>
00
User supplied mileage
Cal . Year: 1980
SAN FRANCISCO CA
Ven. Type
Veh. Speeds
VMT Mix
Composite Emissi
Total HC
Exhaust CO
Exhaust NOX
User suppl i ed m
Cal . Year: 1988
SAN FRANCISCO CA
Veh. Type:
Veh. Speeds:
Ant i -

LDGV
accrua 1 di st r
I/M Program:
tarn. Pro'gram:
Period 1 RVP:
LDGT1
19.6 19.6
0.700 0.161
on Factors (Gm/Mile)
6.40 8.22
46.69 61 .52
2.95 3.31
i 1 eage
Ant i -

LDGV
19.6
accrual distr
I/M Program:
tarn. Program:
Period 1 RVP:
LDGT1
19.6
i but i ons
No
No
11.5
LDGT2
19.6
0.076
15.56
80.70
4.75
i but i ons
No
No
11.5
LDGT2
19.6
, veh registrat
Ambi ent
Operat i ng
Mi nimum
Period
LDGT

10.57
67.67
3.77
, veh reg
Ambi ent
Operat i ng
Mi nimum
Period
LDGT

Temp:
Mode:
Temp :
2 RVP:
ion distributions.
78 . 1
20.6
60.
11.5
HDGV
19
0
25
209
7
i st rat
Temp:
Mode:
Temp :
2 RVP:
.6
.034
.29
.39
. 12
ion d i
78. 1
20.6
60.
11.5
HDGV
19
.6
/ 78. 1 / 78
/ 27.3 / 20
(F)
Peri
LDDV
19.6
0.005
0.60
1 .48
1 .48
s t r ibut i ons
/ 78. 1 / 78
/ 27.3 / 20
(F)
Peri
LDDV
19.6
. 1 (F) Region
.6 Al t i tude
Maximum Temp
od 2 Start Yr
Low
500
84.
1988
LDDT HDDV
19.6 19
0.001 0
0.97 4
2.11 13
1.94 26

. 1 (F) Region
.6 Al t i tude
Maximum Temp
od 2 Start Yr
6
016
21
10
33

Low
500
84.
1988
LDDT HDDV
19.6 19
6
Ft .
(F)
MC
19.6
0.007
9. 27
28.79
0.55

Ft .
(F)
MC
19.6


A 1 1 Veh

7.986
56.281
3.633



A 1 1 Veh


-------
VMT Mix:
               0.654
                          0. 174
                                     0.083
                                                          0.040
                                                                     0.0)2
                                                                                0.004
                                                                                          0.028
                                                                                                     0.005
Composite Emission Factors
Total HC: 3.18
Exhaust CO: 20 . 1 2
Exhaust NOX: 1 .32
User supplied mi
Cal . Year: 1990
SAN FRANCISCO CA
Veh. Type:
Veh . Speeds :
VMT Mi x :
(Gm/Mi le)
4.95
37.55
2.04
7.11
45.42
2.55
1 eage accrual distributions
I/M
Ant i -tarn.
Program:
Program:
Period 1 RVP:
LDGV
19.6
0.643
Composite Emission Factors
Total HC: 2.74
Exhaust CO: 17.10
Exhaust NOX: 1 .05
LDGT1
19.6
0. 185
(Gm/Mi le)
4.23
30.76
1 .76
No
No
11.5
LDGT2
19.6
0.083
5.92
37.58
2. 15
M120 Warning: MOBILE4.1 does not model most
requirements; Emission Factors
User supplied mi
Cal . Year: 2000
SAN FRANCISCO CA
Veh. Type:
Veh . Speeds :
VMT Mix:
leage accrual distr
I/M
Ant i - tarn.
Peri
LDGV
19.6
0.602
Composite Emission Factors
Total HC: 2.23
Exhaust CO: 12.12
Exhaust NOX: 0.68
Program:
Program:
od 1 RVP:
LDGT1
19.6
0.219
(Gm/Mi le)
2.88
16.86
1.15
i but i ons
No
No
11.5
LDGT2
19.6
0.087
3.23
20.00
1 . 23
5.65
40. 10
2.21
14.28
104.66
5.71
0.52
1 .45
1 .49
0.84
1 . 79
1.81
2.
1 1 .
18.
.73
.66
.96
6.99
19 .48
0.83
4. 224
28. 1 18
2.215
, veh registration distributions.
Ambi ent
Operat i ng
Mi nimum
Period
LDGT

4.75
32.87
1 .88
Temp: 78 . 1
Mode: 20.6
Temp: 60.
2 RVP: 11.5
HDGV
19.6
0.041
11.61
83. 10
5.55
1993 and later Clean
for CY 1993 or later
, veh registration di
Ambi ent
Operat i ng
Mi nimum
Period
LDGT

2.98
17.75
1 . 18
Temp : 78 . 1
Mode: 20.6
Temp: 60.
2 RVP: 11.5
HDGV
19.6
0.041
7.14
36.89
4.50
/ 78. 1 / 78
/ 27.3 / 20
(F)
Peri
LDDV
19.6
0.008
0.56
1 .50
1 .52
. 1 (F)
.6 Al
Reg i on :
t i tude :
Maximum Temp:
od 2 Start Yr:
LDDT
19.6
0.003
0.90
1 .85
1 .84
: Low
: 500.
: 84.
: 1988
HDDV
19
0
2
1 1 .
18.
.6
.031
.49
. 17
.00
Ft .
(F)
MC
19.6
0.005
6.84
19.45
0.83


Al 1 Veh

3.638
23. 71 1
1 .988
Air Act
are affected.
st ri but i ons
/ 78. 1 / 78
/ 27.3 / 20
(F)
Peri
LDDV
19.6
0.001
0.47
1 .39
1.13

. 1 (F)
.6 Al

Reg i on
t i tude
Max imum Temp :
od 2 Start Yr
LDDT
19.6
0.001
0.79
1 .69
1 .46

: Low
: 500.
: 84.
: 1988
HDDV
19
0
2
10
8
.6
.045
. 14
. 21
.43

Ft .
(F)
MC
19.6
0.004
6.78
19.45
0.83



Al 1 Veh

2.670
14.787
1 .339
                                                                                                                                            tn
                                                                                                                                            I
                                                                                                                                            U>
                                                                                                                                            vo

-------
                              5-40


     5.1.3  Anti-Tampering Program

     Example 7  provides  an example  of  the modeling  of an  anti-
tampering program to reduce emissions.   All of the other settings
are  the  same  as were used  in  Example 6.   The  anti-tamper ing
program  modeled has  the  following  characteristics:    Start  data
1984, oldest model year  vehicles  subject to the  ATP  requirements
of   1975,   newest   model  year   vehicles   subject  to  the   ATP
requirements of  2020  (meaning  that  all vehicles  of model  years
1975 and  later  are  covered),  light-duty gas vehicles are the only
vehicle  type subject  to  the  ATP   requirements  (light-duty  gas
trucks  and  heavy-duty  gas  vehicles  are  exempt),   centralized
program,  annual frequency of  inspection,  50 percent  compliance
rate,   and   inspections   are   performed  for   air   pump  system,
catalyst, fuel  inlet  restrictor,  evaporative  control  system,  PCV
system,  and gas  cap.    No tailpipe lead  detection  test or  EGR
system  inspection  is  included  in this program.   Note that  the
evaporative  emission  control  system   inspection  and  gas  cap
inspection  are both  required;   as   discussed   in  section  2.2.6,
credit  is  provided  for  evaporative emission  system  inspections
only if a gas cap inspection  is also given.

     The  ATP  described  by  this   example  is  for  illustrative
purposes  only,  and   does  not  reflect  the  situation  in  San
Francisco, CA.
                                                                07/91

-------
1           PROMPT
MOBILE4.1 UG  EXAMPLE
1           TAMFLG
1           SPDFLG
1           VMFLAG
1           MYMRFG
1           NEWFLG
1           IMFLAG
1           ALHFLG
2           ATPFLG
5           RLFLAG
1           LOCFLG   -
1           TEMFLG   -
3           OUTFMT
4           PRTFLG
1           IDLFLG
1           NMHFLG
1           HCFLAG
84 75 20  2111  11 050
1  80  19.6 75.0  20.6
SAN FRANCISCO CA C
1  88  19.6 75.0  20.6
SAN FRANCISCO CA C
1  90  19.6 75.0  20.6
SAN FRANCISCO CA C
1  00  19.6 75.0  20.6
SAN FRANCISCO CA C
  7: ATPFLG = 2  (ANTI-TAMPER ING PROGRAM), LAPSY =  1984,  NO I/M
2 = READ ATP PARAMETER CARD.

-  READ IN LOCAL AREA PARAMETERS AS 2ND REQ SC REC
-  CALCULATE EXHAUST TEMPERATURES
   DO NOT PRINT HC  COMPONENTS
   22211222
 27.3 20.6
 60.  84. 11.5  11.5  88
 27.3 20.6
 60.  84. 11.5  11.5  88
 27.3 20.6
 60.  84. 11.5  11.5  88
 27.3 20.6
 60.  84. 11.5  11.5  88
                    ATP PARAMETERS: START,  1ST MVR,  LAST MVR, . VEH TYPES, INSP PGM  TYPE  & FREQ, COMPLIANCE, DISABLE
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
   1ST REQ SC REC:  IREJN.ICY,
LAP REC: SCNAME,RVPAST,TEMMIN
SPD(1),AMBT,PCCN,PCHC,PCCC
.TEMMAX.RVPBAS.RVPIUS,IUSESY
SPD(1),AMBT.PCCN.PCHC,PCCC
.TEMMAX.RVPBAS.RVPIUS,IUSESV
SPD(1),AMBT.PCCN.PCHC,PCCC
.TEMMAX.RVPBAS.RVPIUS, IUSESY
SPD(1).AMBT.PCCN.PCHC,PCCC
.TEMMAX.RVPBAS.RVPIUS,IUSESY
                                                                                                                                         Oi

                                                                                                                                         •P-

-------
MOBILE4.1 UG EXAMPLE 7: ATPFLG = 2  (ANTI-TAMPER ING PROGRAM), LAPSY  =  1984,  NO  I/

Anti-tampering program selected:

    Start year (January 1):             1984
    First model year covered:           1975
    Last model year covered:            2020
    Vehicle types covered:              LDGV

    Type:                               Centralized
    Frequency:                          Annual
    Compliance Rate:                    50.0%

    Air pump system disablements:       Ves
    Catalyst removals:                  Ves
    Fuel inlet restrictor disablements: Yes
    Tailpipe lead deposit test:         No
    EGR disablement:                    No
    Evaporative system disablements:    Yes
    PCV system disablements:            Yes
    Missing gas caps:                   Yes

Total HC emission factors include evaporative HC emission  factors.
Cal.  Year:  1980
                       I/M Program: No
                 Anti-tarn. Program: Yes
  Ambient Temp: 78.1 / 78.1 / 78.1 (F) Region: Low
Operating Mode: 20.6 / 27.3 / 20.6   Altitude:  500. Ft
SAN FRANCISCO CA
Mi nimum
Period 1 RVP:
Veh. Type LDGV
Veh. Speeds
VMT Mix
Compos i te Er
Total HC
Exhaust CO
Exhaust NOX
19.6
0.688
ni ss i on Factors
8.22
54.96
3.11
LDGT1
19.6
0. 142
(Gm/Mi le)
9.38
62.89
3.26
11.5
LDGT2
19.6
0.070

16.20
82.04
4.68
Period 2
LDGT



1 1
69
3



64
23
73
Temp :
RVP:
60.
11.5
HDGV
19
0

29
226
7
.6
.031

.05
.27
.39
(F)


Per
LDDV
19
0

0
1
1
6
005

66
56
51
Max i mum
Temp
iod 2 Start Yr
LOOT
19.6
0.001

0.99
2.13
1 .96
84.
1988
HDDV
19
0

5
16
30
6
052

48
24
06
(F)

MC
19.
0.

9.
33.
0.



6
01 1

71
63
47


Al 1



9
60
4


Veh



415
699
745
Cal.  Year: 1988
                       I/M Program: No
                 Anti-tarn. Program: Yes
  Ambient Temp: 78.1 / 78.1 / 78.1 (F) Region: Low
Operating Mode: 20.6 / 27.3 / 20.6   Altitude:  500. Ft.
SAN FRANCISCO CA
                      Period  1 RVP:  11.5
                                              Minimum Temp:   60.  (F)
                                              Period 2 RVP:  11.5
                                 Maximum Temp:  84. (F)
                            Period 2 Start Yr: 1988
Veh. Type
Veh. Speeds
VMT Mix
Compos i te Er
Total HC
Exhaust CO
Exhaust NOX
LDGV
19.6
0.639
nission Factors
4.33
28.34
1 .70
Cal . Year: 1990 I/M
Ant i -tarn.
LDGT1
19.6
0. 152
(Gm/Mi 1 e)
6.20
40.56
2.14
Program:
Program:
LDGT2
19.6
0.076
8.33
47.98
2.67
No
Yes
LDGT

6.91
43.03
2.32
Ambient
Operat i ng
HDGV
19
0
1 7
128
5
Temp :
Mode :
6
036
68
80
96
78. 1 /
20.6 /
LDDV
19
0
0
1
1
78
27
6
013
62
57
57
1 /
3 /
LDDT
19.6
0.003
0.79
1 .72
1 .77
78.1 (F)
20.6 Al
HDDV
19
0
3
13
21
Reg i on
t i tude
6
072
40
95
52
Low
500.
MC
19.
0.
6.
22.
0.
Ft .

6
009
36
7 1
80

Al 1

5
33
3

Veh

300
846
412


-------
SAN FRANCISCO CA
                      Period  1 RVP:  11.5
  Minimum Temp:  60. (F)
  Period 2 RVP: 11.5
     Maximum Temp:  84. (F)
Period 2 Start Yr: 1988
Veh. Type LDGV
Veh. Speeds
VMT Mix
Compos its En
Total HC
Exhaust CO
Exhaust NOX
19.6
0.628
ni ss i on Factors
3.77
24.55
1 .43
LDGT1
19
0
6
163
LDGT2
19
0
6
077
LDGT




HDGV
19
0
6
037
LDDV
19
0
6
009
LOOT
19
0
.6
.002
HDDV
19
0
6
076
MC
19
0
6
008
Al 1 Veh


(Gm/Mi 1e)
5
34
1
39
05
89
7
40
2
14
33
28
5
36
2
95
06
01
14
105
5
87
70
78
0
1
1
69
67
63
0
1
1
.93
.90
.87
3
13
20
03
30
07
5
21
0
93
95
82
4.632
29. 188
3.151
M120 Warning: MOBILE4.1 does not model  most  1993 and later Clean Air Act
              requirements; Emission  Factors  for CY 1993 or later are affected.
Cal.  Year: 2000
                        I/M Program:  No
                 Anti-tarn. Program:  Yes
SAN FRANCISCO CA
                      Period  1 RVP:  11.5
  Ambient Temp: 78.1 / 78.1 / 78.1 (F) Region: Low
Operating Mode: 20.6 / 27.3 / 20.6   Altitude:  500. Ft
                                               Minimum Temp:   60.  (F)
                                               Period 2 RVP:  11.5
                                 Maximum Temp:  84.
                            Period 2 Start Yr:  1988
                        (F)
Veh. Type
Veh. Speeds
VMT Mix
Compos i t e Er
Total HC
Exhaust CO
Exhaust- NOX
LDGV
19.6
0.589
ni ss i on Factors
2.65
15.20
0.77
LDGT1
19.6
0.191
(Gm/Mi le)
3.66
18.91
1 .24
LDGT2
19.6
0.080
4.03
21.01
1 .29
                                                 LDGT
                                                 3.77
                                                19.53
                                                 1 .25
HDGV
19.6
0.038
9.62
44.89
4.66
LDDV
19.6
0.002
0.63
1 .60
1 .37
LDDT
19.6
0.002
0.92
1 .84
1 .68
HDDV
19.6
0.092
2.21
1 1 .39
9.70
MC
19.6
0.007
5.48
21 .44
0.83
Al 1 Veh


3. 188
17. 128
1 .877

-------