United States Air and Radiation EPA420-P-98-007
Environmental Protection May 1998
Agency
Program User Guide for
Interim Vehicle Clean Screening
Credit Utility
DRAFT REPORT
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May 7,1998
Transmittal of the Draft "Description and Documentation for Interim Vehicle Clean
Screening Credit Utility"
EPA is today releasing draft guidance on the interim use of clean screening methodologies in
state Inspection and Maintenance (I/M) programs. The purpose of the guidance is to share
technical information with states and other interested parties, and to advise them of certain types
of I/M changes EPA is inclined to approve, should states choose to incorporate them into existing
or planned I/M programs. The draft guidance is in the form of two documents and a computer
program. One document addresses concepts and documents the derivation of the credit loss
estimates. The other document provides detailed steps for use of the FORTRAN utility program
which is executed before executing MOBILESb.
The clean screening concepts described in the draft guidance are potentially of considerable
importance to those involved in I/M planning and implementation. In general, clean screening is
aimed at making I/M programs more cost effective by focusing inspections on cars more likely
than others to be high emitters in need of repair. Clean screening can be used to reduce the
number of cars required to be inspected each year-with less than a proportional loss of emission
reduction benefit—which can lead to a more cost-effective I/M program.
Please note that all credit estimates in this draft guidance are not final, and may change as a result
of new data or insights brought to EPA's attention during this review and comment process.
Credit loss estimates for vehicle emitter profiling will change, as EPA continues to make
refinements to this part its analysis. Even once finalized, EPA may from time to time revise the
guidance to reflect the best available data and understanding of clean screening options.
The draft guidance outlines three broad concepts which could be used to excuse likely low
emitters from traditional I/M testing: remote sensing, vehicle emitter profiling, and model year
exemptions. The guidance provides brief background and summary information on each of the
three concepts, comments on the practical application of clean screening in an operating or
planned I/M program, analyses of the probable credit ramifications associated with each
approach based on data sets currently available to EPA, instructions on how to calculate rough
estimates of the credit loss each methodology would likely cause in a specific I/M program, and a
list of references EPA used to prepare the draft guidance.
In preparing this draft guidance, EPA considered a variety of sources and data sets currently
available, which are listed in the "References" section of the guidance. The majority of
information available comes from analytical studies, pilot programs, and modeling exercises
aimed at predicting the immediate credit effect states could expect to experience when choosing
to implement clean screening in an I/M program. While two of the concepts outlined in the
guidance (RSD and model year exemption) are not new, they have not yet been used as a clean
screen in any I/M program. Consequently, there is no large body of real-world application data.
Likewise, utilizing vehicle emitter profiling to identify clean vehicles is fairly new concept as a
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clean screening option, rather than a tried and true approach. In addition, EPA has had to develop
a modeling approach for using information on immediate credit effects to predict credit effects in
future years when the mix and condition of cars on the road will be different. For these reasons,
EPA is particularly interested in receiving comments on the following:
• additional data sets and analysis not referenced in the draft documents
• the analytical approaches used in determining the modeling protocol for both RSD and
vehicle emitter profiling, and any alternatives which may be useful
• options on how to keep an a vehicle emitter profile up to date for a given area without
compromising the technical foundation of the profile
• how EPA and states should approach the ongoing evaluation of clean screening programs in
operation
EPA is soliciting comment on the draft guidance for 60 days, until July 11, 1998. Comments can
be submitted electronically, by mail, or by FAX, at the following locations:
Electronically, to Joe Somers at: somers.joseph@epa.gov
By mail: Joe Somers By FAX: 734/214-4821
U.S. EPA
Assessment and Modeling Division
2000 Traverwood Drive
Ann Arbor, MI 48105
Phone: 734/214-4321
Additionally, EPA will make every effort to include a discussion of the clean screen guidance at
any EPA/stakeholder meetings which occur during the comment period. Once EPA has reviewed
the comments and incorporated them appropriately, we will finalize the guidance for release and
immediate use. We expect this to take place in the fall of 1998.
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Table of Contents
1.0 BACKGROUND AND SUMMARY 1
2.0 DESCRIPTION OF CLEAN SCREENING 1
3.0 CLEAN SCREENING EFFECTS 1
3.1 Basic Clean-Screening Effect Methodology 2
3.2 Options for Fleet Coverage for RSD 3
3.2.1 Option 1: Commitment to a Level of Effort 4
3.2.2 Option 2: Commitment to a Specific Fleet Coverage 5
3.3 Clean-Screening Effectiveness 7
4.0 CLEAN-SCREENING UTILITY 8
4.1 Clean-Screening Utility Input Structure 8
4.1.1 Control Section of Input File 9
4.1.2 Filenames Section 10
4.1.3 RSD Fleet Coverage Option 1: Data Section 11
4.1.4 RSD Fleet Coverage Option 2: Data Section 13
4.1.5 Program 5: Clean Screening Data Section 14
4.1.6 User Supplied RSD Based Clean Screening Effectiveness 16
4.1.7 User Supplied RSD-Based Clean-Screening Vehicle Fractions 18
4.1.8 User Supplied Vehicle Emission Profiling Effectiveness 19
4.1.9 User Supplied Vehicle Emission Profiling Fractions 21
4.2 Using Clean-Screening I/M Credits with MOBILES 23
APPENDIX A
List of Records for RSD Utility 26
APPENDIX B
Example Clean-screening Input Files 29
Example #1: RSD Based Clean-screening with Commitment to Level of Effort
30
Example #2: RSD Based Clean-screening with Commitment to Specific Fleet Coverage
32
Example #3: VEP Based Clean-screening
35
Example #4: RSD Based Clean-screening with Commitment to Level of Effort
and With Alternate Effectiveness and Excused Fractions 38
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1.0 BACKGROUND AND SUMMARY
"Clean screening" is a generic term for methods used to identify vehicles which are low
emitting for purposes of exempting these "clean" vehicles from the next scheduled test in the
periodic vehicle inspection and maintenance (I/M) program required by some state and local
areas. In September 1996, EPA released a document entitled "User Guide and Description for
Interim Remote Sensing Program Credit Utility" (EPA 420-R-96-004) providing details on a
program for States to obtain extra I/M emission credits for using remote-sensing devices (RSD)
to find high-emitting vehicles and requiring them to obtain early (out of sequence) I/M tests.
That guidance remains unchanged. The original release of the RSD credit utility did not include
options for using RSD for clean screening. This program option has now been added to the
utility along with other clean screening methods, including vehicle emission profiling (VEP).
This user guide is intended as a companion document to the original user guide. Users should
refer to that document for information about RSD options to identify high-emitting vehicles.
2.0 DESCRIPTION OF CLEAN SCREENING
The original objective of RSD was to identify high emitters in the vehicle fleet. However,
the measurement of the emissions of vehicles can also be used to identify "clean" vehicles with a
high probability of passing its periodic inspection test. It is expected that by exempting these
vehicles from the next periodic inspection, I/M programs can reduce the burden on the inspection
system, reduce vehicle owner costs, and increase convenience and program acceptance. A more
detailed description of how remote-sensing is done is contained in the original 1996 user guide.
Other methods can be used to identify clean vehicles for exemption from the I/M program.
One method, VEP is included in this utility. This method uses known factors about vehicle
emissions based on large I/M databases with historic records of failures for different vehicle
models to choose low-emitting vehicles for exemption without explicit emission measurements.
Another option for clean screening is to exempt entire model years from inspection. Model years
can be exempted using parameters within the MOBILES model I/M Program Descriptive Record
without the use of this utility.
A separate document, "Description and Documentation for Interim Vehicle Clean Screening
Credit Utility," (EPA 420-P-98-008) provides a more detailed description of the various
approaches to clean-screening programs, the emission benefit impacts of clean-screening, and
how the emission estimates were determined. This document is the basis for the default
effectiveness values used in this utility.
3.0 CLEAN SCREENING EFFECTS
The EPA MOBILES model stores the credits for all I/M programs in separate data files that
are read during MOBILE runs. EPA can modify or supplement these files to add new data
and/or options that were not included in the original release of the model, without the need for a
1
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new version of the MOBILE model itself. The credits in the I/M credit files can thus be adjusted,
as needed, to reflect the operation of clean-screening scenarios.
Since clean-screening excuses vehicles from their next scheduled inspection, the primary
effects clean-screening methods have on the benefits of any specific I/M program is to reduce the
number of vehicles which receive repairs. The purpose of this utility, then, is to reduce the
benefit attributed to I/M programs in the I/M credit file to reflect the effect of clean-screening
vehicle exemptions. Because excusing vehicles from inspection reduces the number of vehicles
checked for evaporative emission problems in those I/M programs including evaporative
emission checks, the evaporative program benefits must also be reduced.
3.1 Basic Clean-Screening Effect Methodology
The clean-screening effects are a function of two basic parameters: 1) the fraction of all
vehicles in each model year that is eligible to be excused from their next scheduled inspection,
and 2) the effectiveness of the clean-screening method at identifying vehicles which are truly
clean. The determination of the fraction of eligible vehicles and effectiveness is done for each
model year (vehicle age) in the fleet. Only vehicles with sufficient information to allow for the
clean-screening determination are eligible vehicles.
Mathematically, the process to adjust the I/M credits is as follows:
New Creditmip = Old Credit^ * Fm * Emjp (1)
Where:
Old Credit = I/M credit from the periodic inspection program;
F = Adjusted fraction of the inspected fleet eligible for clean-screening
(referenced below as fleet coverage);
E = Effectiveness of clean-screening at identification of clean vehicles;
m = Quantity is a function of vehicle model year; and
p = Quantity is a function of pollutant (i.e., HC, CO or NOx).
In the equation, the influence of the underlying I/M program is represented by the variable
Old Creditmp which is chosen from the already-released I/M credits used with the MOBILES
model. The variables Fm and Emp in the equation represent the clean-screening fleet coverage and
the remote-sensing effectiveness. The fleet coverage is determined as explained in the original
user guide (and repeated below). Only coverage options 1 and 2 are allowed for clean-screening
scenarios.
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3.2 Options for Fleet Coverage for RSD
Fleet coverage is the fraction "F" in the equation given earlier. The clean-screening utility
allows a state two options for fleet coverage for RSD-based scenarios. The first option is
commitment to a level of effort in which a state commits to a specific number of vehicles that
will have valid RSD tests (i.e., valid readings of HC/CO and NOx (if a NOx cutpoint is used) on
a specific vehicle, valid recording of license plate, and ability to contact vehicle owners for any
required I/M test) in a given time period. The RSD clean-screening utility will internally convert
the number of RSD tests to fleet coverage assuming the vehicles to be eligible for clean-
screening must receive two or more valid RSD tests. The second option is to commit to a
specific RSD fleet coverage in which a certain percentage of the fleet will receive two or more
valid RSD tests. These options are discussed in detail in Sections 3.3.1 and 3.3.2 in the original
user guide for RSD.
The third vehicle coverage option available in the original 1996 utility (committing to find a
specific number of I/M failures using RSD) cannot be applied to RSD clean-screening programs
and is not discussed here.
Vehicle Emission Profiling (VEP) programs assume complete (100%) vehicle coverage and
are unaffected by the user choice of fleet coverage options.
Option I: Commitment to a Level of Effort
The user specifies the number of valid remote-sensing measurements done. The utility
estimates vehicle coverage from this information using coverage information derived from a
Poisson distribution. The default effectiveness values for RSD-based clean-screening in this
utility assume that each excused vehicle has had at least two valid RSD readings. The method
used to make the estimate is described in a later section.
Option 2: Commitment to a Specific Fleet Coverage
The user specifies the fraction of the fleet in each model year that is seen using remote-
sensing. This fraction should be only the fraction of the fleet which has had sufficient valid
remote-sensing measurements to allow an affirmative decision regarding exemption from the
next I/M inspection. For example, if a state decides (to minimize the chance that a dirty vehicle
will be excused from its next scheduled inspection) that at least two valid passing RSD readings
are needed to make a vehicle eligible for exemption from I/M, this fraction should represent the
portion of the fleet that has received two RSD readings.
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The default effectiveness values for RSD based clean-screening in this utility assume that
each excused vehicle must have at least two valid RSD readings. If a state decides that some
other minimum number of valid RSD readings (e.g., one or three) will be used in their RSD
program, then the default values for the effects of RSD based clean-screening (based on two
valid readings) cannot be used. Section 4.1 describes how the user may enter the alternate
effectiveness values if some other minimum number of valid RSD readings are required.
Since newer vehicles travel more and normally make up a larger fraction of all vehicles in
an area than older vehicles, newer model years will tend to be more likely to be seen by a
remote-sensing device than older vehicles. As a result, the fraction of all vehicles in a given
model year which are eligible for exemption from its next I/M inspection will be larger for newer
model years than for older model years. Therefore, a program whose intention it is to exempt a
given fraction of the fleet will exempt mostly the newer model years.
3.2.1 Option 1: Commitment to a Level of Effort
This is the simplest of the three options in which a state looks at its resources and commits
to obtaining a specific number of RSD readings per month. In this option, a modified Poisson
algorithm is used to estimate the number of vehicles seen by remote-sensing each year in order to
calculate the fraction of the fleet tested by remote-sensing (factor F). This is necessary, since the
fraction of all vehicles in the fleet which are measured by remote-sensing is a function of the
total number of remote-sensing measurements, but is less than obtained by looking at the number
of RSD readings since some vehicles are seen multiple times by RSD. A Poisson algorithm is a
standard method to model such a situation. This phenomenon was demonstrated in the
California Bureau of Automotive Repair Study done in Sacramento where some individual
vehicles were measured several times over the course of the study. This fraction is a function of
the annual average vehicle miles traveled (VMT) of a vehicle model year at a given age
compared to its VMT when new.
The algorithm used to calculate remote-sensing coverage involves a modification to Lambda
in the Poisson series using the ratio of the VMT of the youngest model year (age) to the VMT of
the model year (age) being estimated. This adjustment uses national average VMT information,
but the VMT information can be modified by the user to reflect local, rather than national
default, information. The form of the equation is as follows:
P = 1.0 - exp( k * -Lambda) (2)
Where k is the ratio of VMTs,
k = VMT(current age)/VMT(age= 1). (3)
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This algorithm is calculated for each model year and gives the probability of measuring
emissions from vehicles of a given model year. One sums the probabilities for each model year
to obtain an overall probability for all vehicles. In addition, as mentioned later, this option
permits the user to specify only vehicles with more than one RSD reading as having sufficient
information to allow an affirmative decision. Such a specification will lower the overall fraction
ofthe fleet seen.
If an I/M program encourages drivers to visit announced RSD sites in hopes of earning an
exemption from I/M inspection, or if this practice develops even without encouragement, the
Poisson-based coverage estimates may not be applicable. Actual experience may be the only
way to determine coverage accurately. The utility allows the actual observed coverage estimates
to be inputted using Option 2 (below).
3.2.2 Option 2: Commitment to a Specific Fleet Coverage
In this option, the user inputs related to remote-sensing effort are replaced by a commitment
to obtain valid remote-sensing readings on a specific fraction of the fleet as determined by the
state. This commitment is for sufficient RSD readings for each vehicle age category (i.e., by
model year) separately to meet the commitment of vehicles for RSD targeting. This requires the
user to supply the number of current vehicles of each age and the number of those vehicles which
are committed to be seen by remote-sensing in the next year.
The default effectiveness values for RSD-based clean-screening in this utility assume that
each excused vehicle must have at least two (2) valid RSD readings. If a state decides that some
other minimum number of valid RSD readings (e.g., 1 or 3) will be used in their RSD program,
then the default values for the effects of RSD-based clean-screening (based on two valid
readings) cannot be used. Section 4.1 describes how the user may enter the alternate
effectiveness values if some other minimum number of valid RSD readings are required.
There are no default values for this fleet coverage option. Some areas may not have
information available regarding the distribution of number of vehicles by age that will likely be
seen twice using RSD methods before the clean-screening program actually begins. One
approach would be to use the level of effort (Option 1) method to define the vehicle coverage for
clean-screening instead of Option 2, where the distribution information is required. Another
approach would be to estimate the distribution for different coverage targets using the same
Poisson methodology as described in Option 1. Table 1 shows the results of using the Poisson
methodology as described in Option 1 to estimate the number of vehicles by age that will likely
be seen twice by RSD. This estimate assumes MOBILES default values for mileage
accumulation and the default passenger car age distribution.
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Table 1
Distribution of the Number of Vehicles by Age Seen Twice by
Remote Sensing Versus a Target Fleet Coverage
Target Fleet Coverage
Vehicle Age 30% of the Fleet 50% of the Fleet 70% of the Fleet
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
47%
40%
41%
39%
36%
34%
31%
29%
27%
25%
23%
21%
20%
18%
17%
15%
14%
13%
12%
11%
10%
9%
8%
7%
7%
71%
64%
65%
62%
59%
56%
53%
50%
47%
44%
42%
39%
36%
34%
32%
29%
27%
25%
23%
21%
20%
18%
17%
15%
15%
89%
84%
85%
82%
80%
77%
75%
72%
69%
66%
63%
60%
57%
54%
51%
48%
45%
43%
40%
37%
35%
32%
30%
28%
28%
For example, about 30% had two or more RSD readings in the California Bureau of
Automotive Repair Study in Sacramento. If this was the target coverage for the proposed RSD-
based clean-screening program, the distribution in the above table for the 30% fleet coverage
could be used as an estimate of the distribution of vehicles seen twice for purposes of calculating
the effects of RSD based clean-screening.
3.3 Clean-Screening Effectiveness
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Clean-screening effectiveness (factor E) refers to the ability of the clean-screening tests to
correctly identify vehicles which would pass an I/M inspection. If assuming that, using remote-
sensing was possible to identify only those vehicles in that fleet that would pass an I/M
inspection, then the effectiveness of remote-sensing for clean-screening would be 100 percent.
In practice, not all vehicles identified by remote-sensing for exemption from inspection would
pass the I/M inspection. In general, there will be a non-linear relationship between the percent of
vehicles excused from their next scheduled inspection and the emissions benefit loss, since the
least dirty cars will be the first to pass. The shortfall in I/M benefit caused by the exemption of
failing vehicles depends primarily on the remote-sensing emission measurement cutpoints
chosen by the program. In vehicle emission profiling (VEP) programs, a variety of factors are
used to identify vehicles for exemption. As in RSD-based clean-screening, the effectiveness of
these programs will depend on how well they can identify only those vehicles that will pass the
I/M inspection. The full derivation of the default values used for clean-screening effectiveness is
discussed in a separate document entitled, "Description and Documentation for Interim Vehicle
Clean Screening Credit Utility," (EPA 420-P-98-008).
Some programs include a functional check of the evaporative pressure and/or purge system.
It is assumed that each vehicle excused from its next scheduled inspection in the periodic
inspection program based on the clean-screening program has an equal probability of having
excess evaporative emissions as those vehicles which are inspected. (This is in contrast to the
non-linear relationship for tailpipe emissions.) This means that the reduction in pressure/purge
effectiveness is directly proportional to the fraction of all vehicles (by age) which are excused
from their next scheduled inspection by the clean-screening program. However, since most
vehicles eligible for clean-screening will be newer model years (with fewer evaporative failures),
the loss in program benefit will be considerably less than the fraction of vehicles excused from
their next scheduled inspection.
The default effectiveness values for RSD-based clean-screening in this utility assume that
each excused vehicle must have at least two (2) valid RSD readings. If a state decides that some
other minimum number of valid RSD readings (e.g., 1 or 3) will be used in their RSD program,
then the default values for the effects of RSD-based clean-screening (based on two valid
readings) cannot be used. Section 4.1 describes how the user may enter the alternate
effectiveness values if some other minimum number of valid RSD readings are required.
The default effectiveness values used by the RSD-based clean-screening utility will assume
that the effectiveness of the underlying I/M program inspections is closer to the effectiveness of
the EVI240 test procedure using the recommended phase-in cutpoints. This is the information
currently available and described in the document cited above. The utility also contains
effectiveness values for RSD-based clean-screening which assume that the effectiveness of the
underlying I/M program inspections is closer to the effectiveness of the EVI240 test procedure
using the recommended final cutpoints. However, the user must specify that the alternate
effectiveness numbers are to be used by the utility, as described in later sections. The more
effective the underlying I/M program is, the more likely it is that clean-screening will excuse
some potentially failing vehicles from their next scheduled inspection, increasing the loss of
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benefit to the I/M program.
4.0 CLEAN-SCREENING UTILITY
4.1 Clean-Screening Utility Input Structure
The updated remote-sensing utility is identical in input structure to the original utility for the
existing RSD options and programs. Much of the description of sections from the original user
guide which may be useful for clean-screening options is repeated in this user guide for
convenience.
The remote-sensing utility is designed to be used once for a scenario selected by the user.
The scenario is for one evaluation calendar year, and each model year is indexed by its age in
that calendar year, not by the model year itself. It is assumed that the number of scenarios that a
user might consider is small enough so that batch run options are not necessary. Each run
requires a single input file which contains all of the information required by the utility and
supplied by the user. The user is prompted for the name (including the path, if not in the local
directory) of the input file.
If the user selects the Vehicle Emission Profiling (VEP) based clean-screening option, the
user must enter both the effectiveness and fraction of vehicles excused from their next scheduled
inspection. There are no default values stored in this utility for those choices and without the
user supplied data, the resulting I/M credits will not reflect the effect of the VEP program.
Guidance on how to determine the effectiveness and fraction of vehicles excused from their next
scheduled inspection for VEP programs can be found in a separate document entitled,
"Description and Documentation for Interim Vehicle Clean Screening Credit Utility," (EPA 420-
P-98-008).
The remote-sensing utility is run by simply invoking its name (RSDNEW.EXE) at the DOS
prompt. The utility will prompt the user on the screen for the name of the input file.
Enter the name of the remote-sensing input file: (default RSD.D)
All inputs have default values. Here, if the user does not enter a name, the utility will look
for a file labeled "RSD.D" in the local directory. Enter the name of the file containing the
control information that has been constructed for the desired scenario. This is the only
interactive user input necessary to run the utility.
The following sections describe how to construct the input file. The input file contains all of
the remaining information needed to calculate the remote-sensing effects, including the location
of the original I/M credit data files and the names and location of the output remote-sensing
credit files.
The input file is structured so that each line (record) begins with an identification number.
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This number indicates what information is contained on that record and allows the records to be
entered in any order. Although some records are mandatory, any records missing from the input
file revert to default values stored in the utility. In this way, only the information that the user
wishes to supply is included in the input file. Any records with a record number of 000 are
considered comment records and are not processed. In addition, text may be added to records
beyond the last formatted data entry on any card to clarify the contents of that record. This
additional text is not read or processed by the utility.
A summary of all of the input records and their contents is shown in Appendix A. Many of
these records do not apply to clean-screening options and are not described in this user guide. A
description of these records and their contents can be found in the original RSD user guide.
4.1.1 Control Section of Input File
Records 001 and 002 are mandatory records.
Record 001 contains the user selection of the fleet coverage option. The format of this record
is (13,11X,I1), meaning the first three characters contain the record number, followed by 11
blank characters, followed by the user selection of Option. Any characters following the user
selection are ignored by the utility, but can be used to annotate the input file. The available
option levels for RSD-based clean-screening are:
1: Commitment to a Level of Effort; and
2: Commitment to a Specific Fleet Coverage
An additional option is available in the RSD utility (Commitment to a Number of Failures),
but this option is not available for use with clean-screening programs. A more complete
description of the third user option is located in the original RSD user guide. Although fleet
coverage is assumed to be 100% for vehicle emission profiling (VEP) options, Record 001 must
be entered. Since Option 2 requires more user input, users who intend to select a VEP clean-
screening scenario should choose Option 1.
Record 002 contains the user selection of I/M program design. The format of this
record is identical to Record 001. For clean-screening, this record must be set to:
5: Clean-Screening Remote-Sensing Program
A more complete description of the other four user options is located in the original 1996
RSD user guide. The user must always enter both Record 001 and 002 in order to use the
remote- sensing utility. The following is an example input of the control section, including some
added comments to add clarity.
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000 Control Section
000
001 2 Option (may be 1, 2, or 3, but may not be 3 if Program Type is 5)
002 5 Program Type (may be 1, 2, 3, 4, or 5)
4.1.2 Filenames Section
In this section, Records 005 through 008 indicate the name and location of the standard I/M
credit data files and Records 015 through 018 determine the location and name of the resulting
remote-sensing adjusted I/M credit data files. Normally, the resulting I/M credit data will be
written to the filenames in Records 015-018. The indicated I/M credit input files are not altered
by the utility. Instead, new replacement credit files are created with the appropriate adjustment
of the I/M credits to reflect the effects of the user specified remote-sensing program.
The format of each record is (I3,1X,A40), meaning the first three characters contain the
record number, the next character is blank, followed by up to 40 characters which indicate the
file name, including any necessary path information. If no path is specified, the data files must
reside in the same (local) directory from which the utility is run. The record numbers for each
file are as follows.
Input Files
Record Description
005: 1981 and newer model year credits
006: 1981 and newer model year Retest-Hybrid credits
007: Pre-1981 model year credits
008: Pre-1981 model year Retest-Hybrid credits
009: Standard pressure/purge credits
010: Retest-Hybrid pressure/purge credits
Output Files
Record Description
Oil: Adjusted standard pressure/purge credits
012: Adjusted Retest-Hybrid pressure/purge credits
015: Adjusted 1981 and newer model year credits
016: Adjusted 1981 and newer model year Retest-Hybrid
017: Adjusted Pre-1981 model year credits
018: Adjusted Pre-1981 model year Retest-Hybrid credits
Since there are default filenames for the standard I/M credit files and the output files, the user
may skip all of these input records and the default names are used. All of the files, however,
10
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must be in the local directory. The following is an example input of the filename section, using
files other than the default filenames, including some added comments to add clarity.
000 User Input and Output Filenames Default Filename
000
005 C:\DATAMM1.D IMDATA.D
006 C:\DATA\IMH.D HYBRID.IMC
007TC1.D TECH12.D
008 TCH.D TECH12.D
009PP.D PPEFFM5.D
010PPH.D PPEFF.D
011PPRSD.D PPM5RSD.D
012PPHRSD.D PPHYRSD.D
015 RSDDAT 11 .D RSDDATA.D
016 RSDD AT A.H RSDD ATA.H
017 TECDAT 11 .D TECDATA.D
018TECDATA.H TECD AT A.H
For maximum flexibility, separate input has been allowed for Retest-Hybrid I/M credits for
the pre-1981 model year vehicles, even though EPA has not calculated separate credits for that
case. For this reason, the default input for that case is identical to the standard input file.
4.1.3 RSD Fleet Coverage Option 1: Data Section
The first vehicle coverage input option requires that the user supply information on the level
of effort which is applied to make a given number of valid vehicle measurements using remote-
sensing. This information includes:
Record Description
021: The number of vehicles in the fleet
022: The number of valid measurements per month that are made using remote-sensing devices
023: The number of times that a vehicle must be seen by RSD before it can be targeted for RSD
based clean-screening. (This value must be "2" for RSD based clean-screening options.)
In addition, the user may supply the average vehicle miles traveled per year by vehicle age to
override the MOBILES default values normally used in the calculations.
The number of vehicles in the fleet represents the population of vehicles which are subject to
the inspection program in the area. This number excludes out-of-area vehicles and vehicles
excused from the inspection. The number of vehicles in the fleet is entered on Record 021. The
format for this record is (I3,1X,I11).
The number of valid measurements per month that are made using remote-sensing devices is
11
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the primary measure of the level of effort related to vehicle coverage. The number of valid
measurements that can be made with remote-sensing devices depends on a great variety of
factors including the number of practical remote-sensing locations, the number of devices
provided, the amount of staff required and available to operate the remote-sensing devices, the
density of vehicles subject to the inspection program at the remote-sensing sites, the number of
hours and days that the remote-sensing devices are operated, the staff allocated to remote-sensing
data processing and the quality of the remote-sensing readings. The number entered by the user
represents the commitment by the program to expend sufficient effort to make that number of
valid measurements in each month. This number is entered on Record 022. The format for this
record is (13,1X,I11).
The number of times that a state determines a vehicle must be seen using remote-sensing
before it can be excused from I/M inspection is entered on Record 023. The default value for this
record is two, and although the utility allows the user to specify up to 11 measurements; the
present EPA effects of RSD-based clean-screening are based on two measurements and give no
additional credit for multiple measurements beyond two. User entry of less than or greater than
two measurements is ignored. The format for this record is (13,1X,I11).
The following is an example input of the Option 1 data section, using values other than the
default values, including some added comments to add clarity.
000 Option 1 Data Section
000
021 810498 No. of vehicles in inspection area default 1000000
022 110808 Valid veh. measurements per month default 50000
023 2 No. times a veh. must be measured default 2 (1-11)
In addition, the user may supply the average vehicle miles traveled per year by vehicle age to
override the MOBILES default values normally used in the calculations. This requires the entry
of 25 separate records (Records 101 through 125). Record 101 contains the mileage
accumulation of vehicles from 0 to 1 year of age. Record 102 contains the mileage accumulation
of vehicles from 1 to 2 years of age, and so forth. Since vehicles are more likely to be measured
if they are driven more, a higher mileage accumulation in proportion to other vehicles increases
the expected number of vehicles of that age that are measured. The default values assume that all
vehicles travel the roadways which are monitored using remote-sensing. If remote-sensing is to
be restricted to only some roadways (such as limited access freeways), the distribution of
mileages should be adjusted to reflect the actual distribution of ages expected on those roadways.
The format for these records is (13,1X,I11).
4.1.4 RSD Fleet Coverage Option 2: Data Section
The second vehicle coverage input option requires that the user supply information on the
fraction of the fleet in each model year which have sufficient valid vehicle measurements using
remote-sensing to allow an affirmative decision on exemption. For example, if it takes, at
minimum, two RSD tests excuse a vehicle from it's next I/M inspection, this is the fraction of the
fleet which will be measured two or more times by RSD. This is a commitment on the part of the
program to apply sufficient resources to find and measure a fraction of each model year using
remote-sensing. The fraction of the fleet measured can vary from model year to model year,
12
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reflecting the difficulty in finding and measuring older model years, which drive less and tend to
avoid some roadway types, such as limited access freeways.
A separate record must be entered for each of 25 vehicle ages (Records 201 through 225).
There are no default values for these inputs. Each record contains the record number, the number
of vehicles of that age which are eligible for targeting each year (i.e., the total number of
vehicles subject to state regulation), and the total number of vehicles of that age in the vehicle
fleet which have sufficient information to allow an affirmative decision on whether to excuse
those vehicles from their next I/M inspection (i.e., the total number of vehicles in the eligible
fleet on which a state commits to obtain valid remote-sensing readings). The entry of both the
number of vehicles subject to the program and the number expected to be eligible for clean-
screening in each vehicle age (instead of a fractional estimate) provides an explicit goal of the
number of vehicles which must obtain valid remote-sensing readings in each vehicle age (model
year) in order to achieve the effect estimated by the utility.
The format for the record is (13,1X,2I11). This means that the first 3 characters contain the
record number, the next character is a blank followed by an integer number in the next 11 spaces,
indicating the total number of vehicles of that age subject to state regulation, followed by another
integer number in the next 11 spaces, indicating the number of vehicles in that age which have
sufficient valid vehicle measurements using remote-sensing to allow an affirmative decision on
whether to excuse those vehicles from their next I/M inspection.
The following is an example input of the Option 2 data section. The example assumes a
MOBILES default distribution of 1 million vehicles and assumes, using remote-sensing, that
50% (500,000) of the vehicles will get two or more valid RSD tests. The distribution of the
500,000 vehicles among the ages of vehicles is taken from the examples in Section 3.3.2 of this
document. The records include some added comments after the numbers to add clarity.
000
000
000
u u u
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
Option 2 Data
Total
49000
79000
83000
82000
84000
81000
77000
56000
50000
51000
50000
54000
47000
37000
24000
19000
Section
Eligible
34761
50544
54025
50922
49644
45433
40895
28084
24103
22659
20835
21060
17122
12565
7579
5573
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Option 2
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age 10
Age 11
Age 12
Age 13
Age 14
Age 15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
13
-------
217
218
219
220
221
222
223
224
225
14000
15000
11000
8000
6000
5000
4000
3000
10000
3807
3774
2556
1715
1185
908
667
459
1529
Option
Option
Option
Option
Option
Option
Option
Option
Option
2
2
2
2
2
2
2
2
2
Age
Age
Age
Age
Age
Age
Age
Age
Age
16
17
18
19
20
21
22
23
24
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
4.1.5 Program 5: Clean Screening Data Section
There are six records that describe the extent and variety of the clean-screening program.
The first five (Records 034 through 038) determine which I/M credits are adjusted to reflect the
effects of clean-screening. Each record contains an integer value which indicates whether the
vehicles represented in that record are subject to clean-screening. If not, no adjustment will be
made to the I/M credits represented by the record. If the integer value is set to " 1", the vehicles
will not be included in the clean screening program and full I/M credits will be retained. If the
integer value is set to "2," the vehicles are assumed to be eligible for clean-screening and the I/M
credits for that vehicle group will be adjusted to reflect the effects of clean-screening on the I/M
benefits. The default value for each of these four records is "2," indicating that all vehicles are
included in the clean-screening program. If the user wishes to exclude vehicle model year
groupings from the clean-screening program, then the appropriate record for those model years
must be entered. The five records cover the following vehicle model year groupings:
034: Clean Screening for Pre-1975 model year vehicles (default value=2)
035: Clean Screening for 1975-80 model year vehicles (default value=2)
036: Clean Screening for 1981-85 model year vehicles (default value=2)
037: Clean Screening for 1986-89 model year vehicles (default value=2)
038: Clean Screening for 1990 and newer model year vehicles (default value=2)
Record 039 indicates the choice of clean-screening options the user wishes to apply to the
vehicles in the fleet. This record must be entered if the program choice is "5", indicating a clean-
screening option. Both remote-sensing device (RSD) and vehicle emission profiling (VEP)
program options are available in the utility. These choices are selected by entry of an integer into
Record 039 indicating the choice. The allowed values are:
RSD using 0.5/200/1000 (%/ppm/ppm) CO/HC/NOx cutpoints
RSD using 0.5/200/1500 (%/ppm/ppm) CO/HC/NOx cutpoints
RSD using 0.5/200/2000 (%/ppm/ppm) CO/HC/NOx cutpoints
1
2
3
4: RSD using 0.5/200 (%/ppm) CO/HC cutpoints (no NOx cutpoint)
5: Vehicle Emission Profile with overall 30% excused
6: Vehicle Emission Profile with overall 40% excused
7: Vehicle Emission Profile with overall 50% excused
14
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8: Alternate clean-screening scenario (user supplied effectiveness and fractions)
Choice #8 is intended as a placeholder for additional options not included in this version of
the utility. There are default values for the effectiveness and fraction of vehicles excused from
their next scheduled inspection for each of the choices (except #8). The following sections
describe in more detail how the user can override these default values.
Record 044 indicates the choice of one of two cases for the effectiveness of the underlying
periodic I/M test. This information has no effect on any vehicle emission profiling (VEP)
program options available in the utility and does not need to be entered for VEP options. If an
RSD-based- clean-screening option is chosen, the default effectiveness values used by the RSD-
based clean-screening utility will assume that the effectiveness of the underlying I/M program
inspections is closer to the effectiveness of the IM240 test procedure using the recommended
phase-in cutpoints. The utility also contains effectiveness values for RSD-based clean-screening
which assume that the effectiveness of the underlying I/M program inspections is closer to the
effectiveness of the IM240 test procedure using the recommended final cutpoints. The user can
specify that the alternate effectiveness numbers are to be used by the utility by entering Record
044. If the user replaces the existing default values for RSD-based clean-screening, entering
Record 044 will have no effect, since the user supplied RSD-based clean-screening effectiveness
values will be used. The allowed values for Record 044 are:
1: RSD clean-screening with EVI240 phase in cutpoint effectiveness; and
2: RSD clean-screening with EVI240 final cutpoint effectiveness.
The format for each clean-screening control record is (I3,1X,I11). This means that the first
3 characters contain the record number. The next character is a blank followed by an integer
number within the next 11 spaces, indicating the user choice for that record. Only Record 039 is
required.
The following is an example input of the clean-screening control data. The example
assumes the user wishes to have a clean-screening program that only allows exemptions for
vehicle that are 1981 and newer model years (Records 034 and 035 = 1). The example assumes
that the user wishes to have a RSD based clean-screening program that uses the 0.5/200/2000
CO/HC/NOx cutpoint set for determination of vehicles to be excused from inspection (Record
039 = 3). The records include some added comments (in comment records and also outside the
format and not read by the utility) to provide clarity.
000
034 1 Clean-screening for Pre-1975 model year vehicles (default=2)
035 1 Clean-screening for 1975-80 model year vehicles (default=2)
036 2 Clean-screening for 1981-85 model year vehicles (default=2)
037 2 Clean-screening for 1986-89 model year vehicles (default=2)
038 2 Clean-screening for 1990 and newer vehicles (default=2)
039 3 Clean-screening choice (default=8)
044 2 Clean-screening IM240 final cutpoint effectiveness (default=l)
15
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4.1.6 User Supplied RSD Based Clean Screening Effectiveness
RSD based clean-screening effectiveness is the fraction of all I/M tailpipe benefits that is
retained by the program, even though vehicles are excused from the inspection. An effectiveness
of 90%, for example, means that 10% of the emissions benefit from all vehicles which would
have failed an I/M inspection are associated with vehicles which are instead excused from the
inspection by RSD based clean-screening. The utility assumes that the loss of tailpipe I/M
benefits is proportional to the fraction of emissions represented by vehicles excused from the
inspection in each model year, not the fraction of vehicles themselves. For example, 50% of the
vehicles might be excused from their next scheduled inspection, but they may represent a much
smaller fraction of overall potential emissions benefit. The fraction of vehicles excused from
their next scheduled inspection (by age) is used directly to calculate evaporative HC benefit
losses. An effectiveness of 100% for RSD based clean-screening would have no effect on the
benefits of I/M programs.
The default effectiveness values for each of these cutpoint combinations assume that a
vehicle must have at least two valid measurements before the vehicle is eligible for clean-
screening. In addition to the data describing the vehicle coverage options, users may enter the
effectiveness of RSD- or VEP-based clean-screening and the fraction of vehicles excused from
their next scheduled inspection by the chosen cutpoints by age. This entry is not required. User
entry will override the default values provided by the utility.
The effectiveness array used for the RSD based clean-screening choices have values for
three model year groupings, four cutpoint combinations and three pollutants (HC, CO and NOx).
The model year groupings are:
1981-1985 model years
1986-1989 model years
• 1990 and newer model years
The effectiveness for 1981-1985 model years is also applied to pre-1981 model years. The
same effectiveness is used for both passenger car and light duty truck benefits for each model
years grouping. The available default RSD cutpoint combinations are:
1: 0.5/200/1000 (%/ppm/ppm) CO/HC/NOx cutpoints
2: 0.5/200/1500 (%/ppm/ppm) CO/HC/NOx cutpoints
3: 0.5/200/2000 (%/ppm/ppm) CO/HC/NOx cutpoints
4: 0.5/200 (%/ppm) CO/HC cutpoints (no NOx cutpoint)
Since the user input of RSD effectiveness overrides the default values, the user input does
not need to conform to these combinations. However, if the RSD effectiveness values entered by
the user do not match the cutpoint combinations described above, the user must also enter the
16
-------
fraction of vehicles excused from their next scheduled inspection, which ought to be consistent
with the user supplied effectiveness values (see the next section). The RSD effectiveness data
entry is optional. It is only required if the user wishes to override one or more of the default
effectiveness values used by the utility with user supplied RSD effectiveness estimates.
A separate record containing user supplied RSD effectiveness may be entered for each of
12 (Records 951 through 962) combinations of cutpoint combinations and model year groupings.
The format for each effectiveness record is (I3,1X,F10.3,F10.3,F10.3). This means that the first
3 characters contain the record number, the next character is a blank followed by a number
(including a decimal) within the next 10 spaces, indicating the effectiveness value that will be
used for HC, followed by another number (including a decimal) within the next 10 spaces,
indicating the effectiveness value that will be used for CO, followed by another number
(including a decimal) within the next 10 spaces, indicating the effectiveness value that will be
used for NOx. Records 951, 952 and 953 override the effectiveness values for Choice #1 for Pre-
1986, 1986-1989 and 1990 and newer model years respectively. Records 954, 955 and 956
override the effectiveness values for Choice #2. Records 957, 958 and 959 override the
effectiveness values for Choice #3. Records 960, 961 and 962 override the effectiveness values
for Choice #4. The user supplied set of RSD-based clean-screening effectiveness values will be
used regardless of the entry of Record 044, described in Section 4.1.5.
The following is an example input of the RSD clean-screening effectiveness data. The
example assumes an effectiveness of 100% (no improperly excused vehicles) for all pollutants,
cutpoint combinations and model year groupings. The records include some added comments (in
comment records and also outside the format and not read by the utility) to provide clarity.
000
000 HC CO NOx
000 Format
951 1.00 1.00 1.00 Choice #1, Pre-1986 model years
952 1.00 1.00 1.00 Choice #1, 1986-1989 model years
953 1.00 1.00 1.00 Choice #1, 1990 and newer vehicles
954 1.00 1.00 1.00 Choice #2, Pre-1986 model years
955 1.00 1.00 1.00 Choice #2, 1986-1989 model years
956 1.00 1.00 1.00 Choice #2, 1990 and newer vehicles
957 1.00 1.00 1.00 Choice #3, Pre-1986 model years
958 1.00 1.00 1.00 Choice #3, 1986-1989 model years
959 1.00 1.00 1.00 Choice #3, 1990 and newer vehicles
960 1.00 1.00 1.00 Choice #4, Pre-1986 model years
961 1.00 1.00 1.00 Choice #4, 1986-1989 model years
962 1.00 1.00 1.00 Choice #4, 1990 and newer vehicles
4.1.7 User Supplied RSD-Based Clean-Screening Vehicle Fractions
Exhaust emission measurements using RSD are assumed not to detect problems with the
evaporative emission control systems. If an I/M program includes a functional inspection of the
evaporative emission control systems (either a gas cap or fuel tank pressure check or an
evaporative system purge check), then excusing those vehicles from the I/M inspection by RSD
17
-------
based clean-screening will reduce the I/M benefits from these evaporative system checks. The
utility does this by reducing the benefits of evaporative emission control system checks by the
fraction of vehicles in that vehicle age that are excused from the inspection by RSD based clean-
screening. For example, if 40% of vehicles of a given age are excused from their next scheduled
inspection by clean-screening, then the benefits of the evaporative system checks for that age are
reduced by 40%.
There is a separate default fraction of vehicles excused from their next scheduled inspection
by age for each default RSD cutpoint combination in the utility. The combinations are described
in the above section regarding RSD-based clean-screening effectiveness. Since the user input of
excused fractions overrides the default values, the user input does not need to conform to these
cutpoint combinations. However, the user must also enter the corresponding effectiveness values
in order to be consistent. This data entry is optional. It is only required if the user wishes to
override one or more of the default excused fraction values used by the utility.
A separate record may be entered for each of 25 (Records 971 through 995) ages. The
format for each excused fraction record is (I3,1X,F10.3,F10.3,F10.3,F10.3). This means that the
first 3 characters contain the record number, the next character is a blank followed by a number
(including a decimal) within the next 10 spaces, indicating the excused fraction that are used for
the choice #1 cutpoint combination, followed by another number (including a decimal) within the
next 10 spaces, indicating the excused fraction that are used for the choice #2 cutpoint
combination, followed by another number (including a decimal) within the next 10 spaces,
indicating the excused fraction that are used for the choice #3 cutpoint combination, followed by
another number (including a decimal) within the next 10 spaces, indicating the excused fraction
that are used for the choice #4 cutpoint combination. Record 971 overrides the excused fractions
for vehicles of age 1. Record 972 overrides the excused fractions for vehicles of age 2, etc.
Record 995 overrides the excused fractions for vehicles of age 25.
The following is an example input of the RSD clean-screening excused fraction data. The
example assumes that 40% of vehicles are excused from their next scheduled inspection for all
cutpoint combinations and ages. The records include some added comments (in comment
records and also outside the format and not read by the utility) to provide clarity.
000
000 Choice #1 Choice #2 Choice #3 Choice #4
u u u
971
972
973
974
975
976
977
978
979
0
0
0
0
0
0
0
0
0
.40
.40
.40
.40
.40
.40
.40
.40
.40
0
0
0
0
0
0
0
0
0
.40
.40
.40
.40
.40
.40
.40
.40
.40
0
0
0
0
0
0
0
0
0
.40
.40
.40
.40
.40
.40
.40
.40
.40
0
0
0
0
0
0
0
0
0
.40
.40
.40
.40
.40
.40
.40
.40
.40
r i_ij_ L
Age
Age
Age
Age
Age
Age
Age
Age
Age
Lid
1
2
3
4
5
6
7
8
9
18
-------
980 0.40 0.40 0.40 0.40 Age 10
981 0.40 0.40 0.40 0.40 Age 11
982 0.40 0.40 0.40 0.40 Age 12
983 0.40 0.40 0.40 0.40 Age 13
984 0.40 0.40 0.40 0.40 Age 14
985 0.40 0.40 0.40 0.40 Age 15
986 0.40 0.40 0.40 0.40 Age 16
987 0.40 0.40 0.40 0.40 Age 17
988 0.40 0.40 0.40 0.40 Age 18
989 0.40 0.40 0.40 0.40 Age 19
990 0.40 0.40 0.40 0.40 Age 20
991 0.40 0.40 0.40 0.40 Age 21
992 0.40 0.40 0.40 0.40 Age 22
993 0.40 0.40 0.40 0.40 Age 23
994 0.40 0.40 0.40 0.40 Age 24
995 0.40 0.40 0.40 0.40 Age 25
4.1.8 User Supplied Vehicle Emission Profiling Effectiveness
Vehicle emission profiling (VEP) can be used as a method to exempt vehicles from
inspection in I/M programs. Like RSD based clean-screening, VEP clean-screening will affect
I/M benefits because some vehicles which would have failed the I/M inspection will be excused
from their next scheduled inspection by clean-screening. As with RSD based clean-screening,
the utility assumes that a 90% effectiveness will result in a 10% loss of I/M benefit for the
fraction of the fleet subject to the VEP program. Unlike RSD based clean-screening, VEP based
clean-screening is assumed by the utility to apply to all vehicles subject to state regulation
included in the program and is unaffected by the user choice of vehicle coverage options. This is
reflected in the calculations by assuming 100% vehicle coverage. Also, VEP effectiveness varies
by age, instead of by model year grouping as for RSD based clean-screening.
The existing flags described in the Clean-screening Data Section 4.1.5 allow the user to
restrict VEP clean-screening only to selected model year ranges. Users may wish to apply VEP
based clean-screening to only vehicles within a certain range of vehicle ages within these model
year ranges, even though a larger range of ages will be subject to the I/M program. This case can
be modeled by entering 100% effectiveness for the ages in a given evaluation calendar year
which will not be subject to VEP based clean-screening. A separate set of I/M credits must be
generated for each evaluation calendar year where VEP based clean-screening is applied.
There are four default choices for VEP clean-screening programs:
5: Vehicle Emission Profile with overall 30% excused (100% coverage)
6: Vehicle Emission Profile with overall 40% excused (100% coverage)
7: Vehicle Emission Profile with overall 50% excused (100% coverage)
8: Alternate clean-screening scenario (user supplied effectiveness and fractions)
Although these choices are available, there are no default effectiveness values available in
19
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this version of the utility. Users must enter the effectiveness values for the users choice of a VEP
program. The set of effectiveness values includes values by age for the three pollutants (HC, CO
and NOx). The user must assure that the user supplied effectiveness values will be consistent
with the user supplied fractions of vehicles excused from their next scheduled inspection
(described below). Only the set of effectiveness values corresponding to the VEP program
choice made by the user will be overridden. This should present no difficulties, since that will be
the scenario used by the utility to calculate the effect of the VEP program on the I/M credits.
EPA's current guidance regarding effectiveness values for VEP is given in a separate document,
"Description and Documentation for Interim Vehicle Clean-Screening Credit Utility," (EPA 420-
P-98-008).
A separate record may be entered for each of 25 (Records 651 through 675) ages. The
format for each effectiveness record is (I3,1X,F10.3,F10.3,F10.3). This means that the first 3
characters contain the record number, the next character is a blank followed by a number
(including a decimal) within the next 10 spaces, indicating the effectiveness value that will be
used for HC, followed by another number (including a decimal) within the next 10 spaces,
indicating the effectiveness value that will be used for CO, followed by another number
(including a decimal) within the next 10 spaces, indicating the effectiveness value that will be
used for NOx. Record 651 overrides the effectiveness for vehicles of age 1. Record 652
overrides the effectiveness for vehicles of age 2, etc. Record 675 overrides the effectiveness for
vehicles of age 25.
The following is an example input of the VEP clean-screening effectiveness data. The
example assumes an effectiveness of 100% (no improperly excused vehicles) for all pollutants
and ages. The records include some added comments (in comment records and also outside the
format and not read by the utility) to provide clarity.
000
000
nnn
u u u
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
HC
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
CO
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
NOx
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
Format
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
20
-------
668 1.00 1.00 1.00 Age 18
669 1.00 1.00 1.00 Age 19
670 1.00 1.00 1.00 Age 20
671 1.00 1.00 1.00 Age 21
672 1.00 1.00 1.00 Age 22
673 1.00 1.00 1.00 Age 23
674 1.00 1.00 1.00 Age 24
675 1.00 1.00 1.00 Age 25
4.1.9 User Supplied Vehicle Emission Profiling Fractions
Vehicle emission profiling (VEP) can affect evaporative emission system check benefits in
the same way as RSD based clean-screening options. The utility assumes that, as for RSD based
clean-screening, VEP clean-screening will reduce the benefits of evaporative emission control
system checks by the fraction of vehicles of that vehicle age that are excused from the inspection
by VEP based clean-screening. For example, if 40% of vehicles of a given age are excused from
their next scheduled inspection by clean-screening, then the benefits of the evaporative system
checks for that age are reduced by 40%.
Although these choices are available, there is no default fraction of excused values
available in this version of the utility. Users must enter the fraction of vehicles excused from
their next scheduled inspection for each age for the users choice of a VEP program. The user
must assure that the user supplied fractions of vehicles excused from their next scheduled
inspection will be consistent with the user supplied effectiveness values (described above). Only
the set of fractions of vehicles excused from their next scheduled inspection corresponding to the
VEP program choice made by the user will be overridden. This should present no difficulties,
since that will be the scenario used by the utility to calculate the effect of the VEP program on
the I/M credits. EPA's current guidance regarding effectiveness values for VEP is given in a
separate document, "Description and Documentation for Interim Vehicle Clean-screening Credit
Utility," (EPA 420-P-98-008).
A separate record is entered for each of 25 (Records 621 through 645) ages. The format for
each excused fraction record is (I3,1X,F10.3). This means that the first 3 characters contain the
record number, the next character is a blank followed by a number (including a decimal) within
the next 10 spaces, indicating the excused fractions that are to be used for the VEP program
selected. Record 621 overrides the excused fraction for vehicles of age 1. Record 622 overrides
the excused fraction for vehicles of age 2, etc. Record 645 overrides the excused fraction for
vehicles of age 25.
The following is an example input of the VEP clean-screening excused fraction data. The
example assumes that 40% of vehicles are excused from their next scheduled inspection for all
ages. The records include some added comments (in comment records and also outside the
format and not read by the utility) to provide clarity.
000 Format
21
-------
621 0.40 Age 1
622 0.40 Age 2
623 0.40 Age 3
624 0.40 Age 4
625 0.40 Age 5
626 0.40 Age 6
627 0.40 Age 7
628 0.40 Age 8
629 0.40 Age 9
630 0.40 Age 10
631 0.40 Age 11
632 0.40 Age 12
633 0.40 Age 13
634 0.40 Age 14
635 0.40 Age 15
636 0.40 Age 16
637 0.40 Age 17
638 0.40 Age 18
639 0.40 Age 19
640 0.40 Age 20
641 0.40 Age 21
642 0.40 Age 22
643 0.40 Age 23
644 0.40 Age 24
645 0.40 Age 25
4.2 Using Clean-Screening I/M Credits with MOBILES
MOBILES uses two external data files which contain the I/M tailpipe credits whenever an
I/M program is specified in the user input. The benefit of I/M program options can be adjusted
by altering the numbers contained in those data files. The remote-sensing I/M credit utility takes
advantage of that fact by adjusting the default I/M credit files to reflect the user supplied
information about the use of clean-screening in the inspection programs. Therefore, any current
version of MOBILES (MOBILESa, March 1993, MOBILE5a_H, February 1995, or
MOBILESb, September 1996) can be used to evaluate clean-screening options.
The first step is to describe the clean-screening program to be modeled in sufficient detail
to create an input file for the remote-sensing I/M credit utility. For some proposed programs, it
may be necessary to estimate or assume some of the necessary input data. However, the inputs
should reflect, as near as possible, the actual expected performance of the clean-screening
program element.
Once the clean-screening program design has been determined, the necessary input data
must be collected together in the input data file. An example input data file is provided with the
clean-screening I/M credit utility which shows the format for all of the necessary input
parameters. The user should carefully read this User Guide to identify the necessary data and to
22
-------
properly locate the data in the input file. The input data file is a simple ASCII text file that can
be changed using any standard editor or word processor. However, the user must save any
changes in a text format. The Remote-Sensing I/M Credit Utility cannot read input files that are
saved in a word processing format.
The next step is to use the remote-sensing I/M credit utility to create an alternative set of
I/M credit data files. The input file designates the names of the default I/M credit files to be used
and the names of the altered (clean-screening) I/M credit files output by the remote-sensing
utility. These filenames can include "path" information if the default I/M credit files are not
located in the local directory. If a path is not specified, the default I/M credit files must be in the
local directory when the remote-sensing utility is run. The new I/M credit files created by the
utility which have been adjusted to reflect the effects of clean-screening will be in the same
directory as the remote-sensing utility is run. These files can be written to a different directory if
a path is specified in the input file.
The remote-sensing utility is run by simply invoking its name (RSDNEW.EXE) at the DOS
prompt. The utility will prompt the user on the screen for the name of the input file. No further
user input is required. The processing is quite lengthy, and some time will pass. There will be
some diagnostic information on the screen during processing. When completed without errors,
the remote-sensing utility will display a completion message on the screen.
Once the processing has been completed, the new I/M credits, adjusted for clean-screening,
will be in the filenames indicated by the user in the input file. Although these files can be
renamed to the MOBILES default I/M credit filenames, there will be no output in MOBILES
which indicates that alternate I/M credits were used. It may be less confusing to access these
alternate I/M credits using the alternate credit option in MOBILES described in the MOBILES
User Guide Section 2.2.5.4. In this case, each input file for MOBILES would indicate which set
of alternate credits was used in the two input records following the I/M Descriptive Record(s).
Since the effect of clean-screening is contained in the alternate I/M credit files, there should
be no need to change any of the normal MOBILES input parameters (other than those to access
the use of alternate I/M credits) to reflect the use of clean-screening. It is very important,
therefore, to carefully choose the right combination of factors in the remote-sensing I/M credit
utility that properly reflect the features of the clean-screening program elements.
If either a functional check of the evaporative pressure or purge system is included as part
of the I/M program, the benefits of these programs must also be replaced with adjusted values.
These are contained in an external data file created by this utility and can be used in
MOBILE5a_H or MOBILESb. MOBILESa does not allow the use of alternate benefits for the
pressure/purge checks.
In MOBILE5a_H, the alternate pressure/purge credits are read automatically from a file
named PPEFF.D located in the same directory as the model is run. These credits are read when
the Program Type in the I/M Descriptive Record is set to four (4), indicating a retest-base hybrid
23
-------
program. As long as the I/M credit file supplied to the model contains the appropriate clean-
screening adjusted I/M credits, the model will properly calculate both the exhaust and
evaporative benefits for the program. The appropriate clean-screening adjusted pressure/purge
credit file should be renamed to PPEFF.D and made available in the local directory when
modeling. The user will need to be careful about which files are being used, because
MOBILE5a_H will not be able to detect and warn the user about inappropriate combinations of
credits. The credits generated by the utility will have an extra record at the beginning of the
PPEFF.D data file. This record contains a brief description of the credits included in the file.
MOBILESb will read and echo this information in the descriptive output of the model (see
below). However, MOBILE5a_H is not designed to read this descriptive record and an error will
occur. If you intend to use MOBILE5a_H, then you must edit this data file to remove the first
(description) record from the data file before using it with MOBILE5a_H.
In MOBILESb, the exhaust emission credits are provided as described for RSD programs
above. However, the credits for the evaporative emissions pressure and purge system check must
be made available in a file named PPEFF.D located in the same directory as the model is run.
These credits are read when the Program Type in the Pressure or Purge Check Descriptive
Record is set to four (3), indicating a Retest-base Hybrid program. The appropriate clean-
screening adjusted pressure/purge credit file must be renamed to PPEFF.D and made available in
the local directory when modeling. You will need to be careful about which files are being used,
because MOBILESb will not be able to detect and warn the user about inappropriate credits.
However, the record describing the altered PPEFF.D file, located in the first record of the file,
will be echoed in the descriptive output of MOBILESb. It will be located just below the
description of the ATP or just below the I/M program if no ATP is included.
24
-------
APPENDIXA
List of Records for RSD Utility
000 comments
001 fleet coverage
1 commitment to level of effort RSD program
2 commitment to specific fleet coverage RSD program
3 commitment to a number of failures RSD program (cannot be used with Program #5)
002 I/M program design
1 basic remote-sensing program
2 test-and-repair remote-sensing program
3 retest hybrid remote-sensing
4 remote sensing only program
5 clean-screening remote-sensing program
005-008 - no user input; indicates name & location of standard I/M credit data input files
015-018 - no user input; indicates location and name of the resulting remote-sensing adjusted
I/M credit data output files
Input Files
005 1981 & newer model year credits
006 1981 & newer model year retest-hybrid credits
007 pre-1981 model year credits
008 pre-1981 model year retest-hybrid credits
009 Standard pressure/purge credits
010 Retest-hybrid pressure/purge credits
Output Files
Oil adjusted standard pressure/purge credits
012 adjusted retest-hybrid pressure/purge credits
015 adjusted 1981 & newer model year credits
016 adjusted 1981 and newer model year only for retest-hybrid credits
017 adjusted pre-1981 model year credits
018 adjusted pre-1981 model year only for retest-hybrid credits
25
-------
024 the age at which vehicles first become eligible for targeting
by remote-sensing, 1 to 24 (default = 1 year)
031 the CO cutpoints to be applied to remote-sensing measurements
for 1974 and older model year vehicles, default = 3%
032 the CO cutpoints to be applied to remote-sensing measurements
for 1975 through 1980 model year vehicles, default = 3%
033 the CO cutpoints to be applied to remote-sensing measurements
for 1981 and newer model year vehicles, default = 3%
041 the test and repair effectiveness for HC emissions, default = 0.5
042 the test and repair effectiveness for CO emissions, default = 0.5
043 the test and repair effectiveness for NOx emissions, default = 0.5
Option 1: Data Section (level of effort)
021 the # of vehicles in the fleet (in inspection area)
022 the # of valid measurements per month that are made using RSD
023 the # of times a vehicle must be failed by RSD before it can be targeted for I/M
inspection; default 1, range 1-11
Option 2: Data Section (specific fleet coverage)
201-225
the # of vehicles for each of last 25 model years that are eligible for RSD targeting and the
# of vehicles of that age that actually receive RSD; the ratio of the two #s is the fleet coverage by
model year
Option 3: Data Section (# of failures)
301-325 The # of vehicles which normally fail I/M annually for each of the past 25 model years
and the # of additional vehicles which are targeted by RSD and also fail the confirmatory I/M
test
The program contains default benefits for RSD. However, the user also has the option of
specifying benefits for option 3 based on a measure of the average excess emission levels of
vehicles failing the remote-sensing cutpoint chosen. Such values would presumably come from
an operating I/M program using RSD. This measure is the ratio of the average excess emissions
of vehicles found at that remote-sensing cutpoint divided by the average emissions of all vehicles
with excess emissions. There are 15 records for each of the three pollutants (HC, CO, and NOx)
corresponding to RSD cutpoints from 0.5% to 7.5%. These records are the ratio of the average
IM240 excess emissions identified per vehicle to the average excess emissions per vehicle in the
fleet as a whole for a particular CO RSD cutpoint. Each of the 15 records has three model year
groupings (1974 and older, 1975-80, and 1981 and newer).
701-715 values for HC
26
-------
801-815 values for CO
901-915 values for NOx
Program #5: Clean-screening Programs
034 Coverage for pre-1975 model year vehicles (default=2) Yes: 1, No:2
035 Coverage for 1975-1980 model year vehicles (default=2) Yes: 1, No:2
036 Coverage for 1981-1985 model year vehicles (default=2) Yes: 1, No:2
037 Coverage for 1986-1989 model year vehicles (default=2) Yes: 1, No:2
038 Coverage for 1990 and newer model year vehicles (default=2) Yes: 1, No:2
039 Selection of Clean-screening Program choice (default=l) range 1-8 where:
Choice 1: RSD using 0.5/200/1000 CO/HC/NOx cutpoints and scanning 2 times
2: RSD using 0.5/200/1500 CO/HC/NOx cutpoints and scanning 2 times
3: RSD using 0.5/200/2000 CO/HC/NOx cutpoints and scanning 2 times
4: RSD using 0.5/200 CO/HC cutpoints (no NOx) and scanning 2 times
5: Vehicle Emission Profile with overall 30% excused (100% coverage)
6: Vehicle Emission Profile with overall 40% excused (100% coverage)
7: Vehicle Emission Profile with overall 50% excused (100% coverage)
8: Alternate clean-screening scenario (user supplied effectiveness and fractions)
044 Indicates the RSD clean-screening EVI240 cutpoint effectiveness to be used.
621-645 contain the user supplied clean-screening fraction of vehicles excused from inspection
by age for the current choice of vehicle emission profiling program, (choices 5-8)
651-675 contains the user supplied clean-screening effectiveness by age and pollutant for the
current choice of vehicle emission profiling program, (choices 5-8)
951-962 contains the user supplied clean-screening effectiveness by model year grouping, RSD
cutpoint and pollutant for RSD clean-screening program options, (choices 1-4)
971-995 contains the user supplied clean-screening fraction of vehicles excused from inspection
by age and RSD cutpoint. (choice 1-4)
27
-------
APPENDIXB
Example Clean-screening Input Files
28
-------
Example #1: RSD Based Clean-screening with Commitment to Level of Effort
000
000 Example #1: RSD Based Clean-screening with Commitment to Level of Effort
000 assuming IM240 phase in level effectiveness
000
000 CONTROL SECTION
to Level of Effort
001
002
000
000
000
000
005
006
1 Option (may be 1, 2, or 3) Commitment
5 Program Type (may be 1 , 2, 3, 4 , or 5
INPUT AND OUTPUT FILENAMES
5<-40 characters total,
IMDATAT . D
IMDATAT . D
same as MOB5->44
1981 & n
'81 & ne-
007 TECH12.D
008 TECH12.D
009 PPEFFM5.D
010 PPEFF.D
Oil PP.D
012 PPH.D
015 IM.D
016 IMH.D
017 TEC.D
018 TECH.D
000
000 GENERAL DATA SECTION
000 -----------
000
021
022
023
000
if Option is not 3) Clean-screening
1981 & newer model year vehicles credits default IMDATA.D
& newer mod. yr veh. Retest-Hybrid cr. default HYBRID.IMC
pre-1974 & 1975-1980 mod. yr veh. cr. default TECH12.D
pre-'74 & '75-'80 mod. yr veh. Retest-Hyb. cr. default TECH12.D
standard pressure/purge effectiveness array default PPEFFM5.D
retest-based hybrid pressure/purge effectiveness default PPEFF.D
CHANGED standard pressure/purge effectiveness default PPM5RSD.D
CHANGED retest-based hybrid press/purge effect default PPHYRSD.D
CHANGED 1981 & newer model year vehicles credits default RSDDATA.D
CHANGED '81 & newer mod. yr veh. Retest-Hybrid cr. default RSDDATA.H
CHANGED pre-1974 & 1975-1980 mod. yr veh. cr. default TECDATA.D
CHANGED pre-'74 & '75-'80 mod. yr veh. Retest-Hyb. cr. default TECDATA.H
5<-llch->15
2400000 No. of veh. in RSD program default 1000000
12000 Valid veh. measurements per month default 50000
2 No. of times a veh. must be scanned (1-11) default 2 for clean-screening
000 Clean-screening Choices (may be 1-8)
000 Choice 1 RSD using 0.5/200/1000 CO/HC/NOx cutpoints and scanning 2 times
000 2 RSD using 0.5/200/1500 CO/HC/NOx cutpoints and scanning 2 times
000 3 RSD using 0.5/200/2000 CO/HC/NOx cutpoints and scanning 2 times
000 4 RSD using 0.5/200 CO/EC cutpoints (no NOx) and scanning 2 times
000 5 Vehicle Emission Profile with overall 30% excused (100% coverage)
000 6 Vehicle Emission Profile with overall 40% excused (100% coverage)
000 7 Vehicle Emission Profile with overall 50% excused (100% coverage)
000 8 Alternate clean-screening scenario (user supplied effectiveness and fractions)
29
-------
000
034
035
036
037
038
039
044
000
2
2
2
2
2
3
1
Clean- screening
Clean- screening
Clean- screening
Clean- screening
Clean- screening
Clean- screening
Clean- screening
for Pre-1975 model year vehicles (default=2)
for 1975-80 model year vehicles (default=2)
for 1981-85 model year vehicles (default=2)
for 1986-89 model year vehicles (default=2)
for 1990 and newer model year vehicles (default=2)
choice (default=8, user supplied effectiveness and fractions)
IM240 phase in cutpoint effectiveness (default=l)
30
-------
Example #2: RSD Based Clean-screening with Commitment to Specific Fleet Coverage
000
000
000
000
000
000
001
002
000
000
000
000
005
006
007
008
009
010
Oil
012
015
016
017
018
000
000
000
000
000
201
202
203
204
205
206
207
208
209
210
211
212
Example #2: RSD Based Clean-screening with Commitment to Specific Fleet Coverage
assuming IM240 final cutpoint level effectiveness
CONTROL SECTION
2 Option (may be 1, 2, or 3) Commitment to Specific Fleet Coverage
5 Program Type (may be 1, 2, 3, 4, or 5 if Option is not 3) Clean-screening
INPUT AND OUTPUT FILENAMES
5<-40 characters
IMDATAT.D
IMDATAT.D
TECH12 .D
TECH12 .D
PPEFFM5.D
PPEFF.D
PP.D
PPH.D
IM.D
IMH.D
TEC.D
TECH.D
OPTION #2 DATA SECTION
Number of vehicles eligible
Total Sent
h->15
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
total, same as MOB5->44
1981 & newer model year vehicles credits default IMDATA.D
'81 & newer mod. yr veh. Retest-Hybrid cr. default HYBRID.IMC
pre-1974 & 1975-1980 mod. yr veh. cr. default TECH12.D
pre-'74 & '75-'80 mod. yr veh. Retest-Hyb. cr. default TECH12.D
standard pressure/purge effectiveness array default PPEFFM5.D
retest-based hybrid pressure/purge effectiveness default PPEFF.D
CHANGED standard pressure/purge effectiveness default PPM5RSD.D
CHANGED retest-based hybrid press/purge effect default PPHYRSD.D
CHANGED 1981 & newer model year vehicles credits default RSDDATA.D
CHANGED '81 & newer mod. yr veh. Retest-Hybrid cr. default RSDDATA.H
CHANGED pre-1974 & 1975-1980 mod. yr veh. cr. default TECDATA.D
CHANGED pre-'74 & '75-'80 mod. yr veh. Retest-Hyb. cr. default TECDATA.H
for clean-screening (two valid readings)
llc->26
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
to
to
to
to
to
to
to
to
to
to
to
to
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
via
via
via
via
via
via
via
via
via
via
via
via
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
age
age
age
age
age
age
age
age
age
age
age
age
0
1
2
3
4
5
6
7
8
9
10
11
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
-10
-11
-12
31
-------
213
214
215
216
217
218
219
220
221
222
223
224
225
000
000
000
000
000
000
000
000
000
000
000
034
035
036
037
038
039
044
000
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
10000
Clean-screening Choices (may be 1-8)
Choice 1 RSD using 0.5/200/1000 CO/HC/NOx cutpoints and scanning 2 times
2 RSD using 0.5/200/1500 CO/HC/NOx cutpoints and scanning 2 times
3 RSD using 0.5/200/2000 CO/HC/NOx cutpoints and scanning 2 times
4 RSD using 0.5/200 CO/HC cutpoints (no NOx) and scanning 2 times
5 Vehicle Emission Profile with overall 30% excused (100% coverage)
6 Vehicle Emission Profile with overall 40% excused (100% coverage)
7 Vehicle Emission Profile with overall 50% excused (100% coverage)
8 Alternate clean-screening scenario (user supplied effectiveness and fractions)
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
1500
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
Total
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh. ,
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
veh
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
sent
to
to
to
to
to
to
to
to
to
to
to
to
to
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
IM
via
via
via
via
via
via
via
via
via
via
via
via
via
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
RSD,
age
age
age
age
age
age
age
age
age
age
age
age
age
12
13
14
15
16
17
18
19
20
21
22
23
24
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
2 Clean-screening for Pre-1975 model year vehicles (default=2)
2 Clean-screening for 1975-80 model year vehicles (default=2)
2 Clean-screening for 1981-85 model year vehicles (default=2)
2 Clean-screening for 1986-89 model year vehicles (default=2)
2 Clean-screening for 1990 and newer model year vehicles (default=2)
3 Clean-screening choice (default=8, user supplied effectiveness and fractions)
2 Clean-screening IM240 final cutpoint effectiveness (default=l)
32
-------
Example #3: VEP Based Clean-screening
1 Option (must choose 1 but has no effect)
5 Program Type (may be 1, 2, 3, 4, or 5 if Option is not 3) Clean-screening
same as MOB5->44
000
000 Example #3: VEP Based Clean-screening
000
000 CONTROL SECTION
000
001
002
000
000 INPUT AND OUTPUT FILENAMES
000
000 5<-40 characters total,
005 IMDATAT.D
006 IMDATAT.D
007 TECH12.D
008 TECH12.D
009 PPEFFM5.D
010 PPEFF.D
Oil PP.D
012 PPH.D
015 IM.D
016 IMH.D
017 TEC.D
018 TECH.D
1981 & newer model year vehicles credits default IMDATA.D
'81 & newer mod. yr veh. Retest-Hybrid cr. default HYBRID.IMC
pre-1974 & 1975-1980 mod. yr veh. cr. default TECH12.D
pre-'74 & '75-'80 mod. yr veh. Retest-Hyb. cr. default TECH12.D
standard pressure/purge effectiveness array default PPEFFM5.D
retest-based hybrid pressure/purge effectiveness default PPEFF.D
CHANGED standard pressure/purge effectiveness default PPM5RSD.D
CHANGED retest-based hybrid press/purge effect default PPHYRSD.D
CHANGED 1981 & newer model year vehicles credits default RSDDATA.D
CHANGED '81 & newer mod. yr veh. Retest-Hybrid cr. default RSDDATA.H
CHANGED pre-1974 & 1975-1980 mod. yr veh. cr. default TECDATA.D
CHANGED pre-'74 & '75-'80 mod. yr veh. Retest-Hyb. cr. default TECDATA.H
000
000 Clean-screening Choices (may be 1-8)
RSD using 0.5/200/1000 CO/HC/NOx cutpoints and scanning 2 times
RSD using 0.5/200/1500 CO/HC/NOx cutpoints and scanning 2 times
RSD using 0.5/200/2000 CO/HC/NOx cutpoints and scanning 2 times
RSD using 0.5/200 CO/HC cutpoints (no NOx) and scanning 2 times
Vehicle Emission Profile with overall 30% excused (100% coverage)
Vehicle Emission Profile with overall 40% excused (100% coverage)
Vehicle Emission Profile with overall 50% excused (100% coverage)
Alternate clean-screening scenario (user supplied effectiveness and fractions)
Clean-screening for Pre-1975 model year vehicles (default=2)
Clean-screening for 1975-80 model year vehicles (default=2)
Clean-screening for 1981-85 model year vehicles (default=2)
Clean-screening for 1986-89 model year vehicles (default=2)
Clean-screening for 1990 and newer model year vehicles (default=2)
8 Clean-screening choice (default=8, user supplied effectiveness and fractions)
UUU L.I1O
000
000
000
000
000
000
000
nnn
034
035
036
037
038
039
000
±ue J-
2
3
4
5
6
7
8
K.
R
R
R
V
V
V
A
2
2
2
2
2
8
33
-------
000 Variable VEPX containing the alternate clean-screening effectiveness
000 by age and age for the clean-screening choice (5-8) . Required Input
000
000 HC CO NOx
000 Format
651 0.50 0.50 0.50 Age 1
652 0.50 0.50 0.50 Age 2
653 0.50 0.50 0.50 Age 3
654 0.50 0.50 0.50 Age 4
655 0.50 0.50 0.50 Age 5
656 0.50 0.50 0.50 Age 6
657 0.50 0.50 0.50 Age 7
658 0.50 0.50 0.50 Age 8
659 0.50 0.50 0.50 Age 9
660 0.50 0.50 0.50 Age 10
661 0.50 0.50 0.50 Age 11
662 0.50 0.50 0.50 Age 12
663 0.50 0.50 0.50 Age 13
664 0.50 0.50 0.50 Age 14
665 0.50 0.50 0.50 Age 15
666 0.50 0.50 0.50 Age 16
667 0.50 0.50 0.50 Age 17
668 0.50 0.50 0.50 Age 18
669 0.50 0.50 0.50 Age 19
670 0.50 0.50 0.50 Age 20
671 0.50 0.50 0.50 Age 21
672 0.50 0.50 0.50 Age 22
673 0.50 0.50 0.50 Age 23
674 0.50 0.50 0.50 Age 24
675 0.50 0.50 0.50 Age 25
000
000 Variable ACSCRN containing the alternate clean-screening fraction excused
000 by age for clean-screening choice (5-8). Required Input
000 Format
621 0.50 Age 1
622 0.50 Age 2
623 0.50 Age 3
624 0.50 Age 4
625 0.50 Age 5
626 0.50 Age 6
627 0.50 Age 7
628 0.50 Age 8
629 0.50 Age 9
34
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630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
000
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
Age 10
Age 11
Age 12
Age 13
Age 14
Age 15
Age 16
Age 17
Age 18
Age 19
Age 20
Age 21
Age 22
Age 23
Age 24
Age 25
35
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Example #4: RSD Based Clean-screening with Commitment to Level of Effort
and With Alternate Effectiveness and Excused Fractions
000
000
000
000
000
n n n
u u u
001
002
000
000
n n n
u u u
000
005
006
007
008
009
010
Oil
012
015
016
017
018
000
000
n n n
u u u
000
021
022
023
000
000
000
000
000
000
000
000
Example #4: RSD Based Clean-screening with Commitment to Level of Effort
with user input of RSD effectiveness and excused fractions.
CONTROL SECTION
1 Option (may be 1, 2, or 3) Commitment to Level of Effort
5 Program Type (may be 1, 2, 3, 4, or 5 if Option is not 3) Clean-screening
INPUT AND OUTPUT FILENAMES
5<-40 characters total, same as MOB5->44
IMDATAT.D 1981 & newer model year vehicles credits
IMDATAT.D '81 & newer mod. yr veh . Retest-Hybrid cr.
TECH12.D pre-1974 & 1975-1980 mod. yr veh. cr.
TECH12.D pre-'74 & '75- '80 mod. yr veh. Retest-Hyb. cr.
PPEFFM5.D standard pressure/purge effectiveness array
PPEFF.D retest-based hybrid pressure/purge effectiveness
PP.D CHANGED standard pressure/purge effectiveness
PPH.D CHANGED retest-based hybrid press/purge effect
IM.D CHANGED 1981 & newer model year vehicles credits
IMH.D CHANGED '81 & newer mod. yr veh. Retest-Hybrid cr.
TEC.D CHANGED pre-1974 & 1975-1980 mod. yr veh. cr.
TECH.D CHANGED pre-'74 & '75- '80 mod. yr veh. Retest-Hyb.
GENERAL DATA SECTION
5<-llch->15
2400000 No. of veh. in RSD program default 1000000
2400000 Valid veh. measurements per month default 50000
2 No. of times a veh. must be scanned (1-11) default 2 for clean-screening
Clean-screening Choices (may be 1-8)
Choice 1 RSD using 0.5/200/1000 CO/HC/NOx cutpoints and scanning 2 times
2 RSD using 0.5/200/1500 CO/HC/NOx cutpoints and scanning 2 times
3 RSD using 0.5/200/2000 CO/HC/NOx cutpoints and scanning 2 times
4 RSD using 0.5/200 CO/EC cutpoints (no NOx) and scanning 2 times
5 Vehicle Emission Profile with overall 30% excused (100% coverage)
6 Vehicle Emission Profile with overall 40% excused (100% coverage)
default
default
default
default
default
default
default
default
default
default
default
cr. default
IMDATA . D
HYBRID. IMC
TECH12.D
TECH12.D
PPEFFM5.D
PPEFF.D
PPM5RSD.D
PPHYRSD.D
RSDDATA . D
RSDDATA . H
TECDATA . D
TECDATA . H
36
-------
7: Vehicle Emission Profile with overall 50% excused (100% coverage)
8: Alternate clean-screening scenario (user supplied effectiveness and fractions)
Clean-screening for Pre-1975 model year vehicles (default=2)
Clean-screening for 1975-80 model year vehicles (default=2;
Clean-screening for 1981-85 model year vehicles (default=2;
Clean-screening for 1986-89 model year vehicles (default=2;
000
000
000
034
035
036
037
038
039
000
000 Variable CLEANX containing the clean-screening effectiveness
000 by pollutant, model year group and choice for Choices #1-4.
000
0.5/200/1000 HC/CO/NOx cutpoints
0.5/200/1500 HC/CO/NOx cutpoints
0.5/200/2000 HC/CO/NOx cutpoints
0.5/200 HC/CO cutpoints (no NOx cutpoint)
2
2
2
2
2 Clean-screening for 1990 and newer model year vehicles (default=2)
3 Clean-screening choice (default=8, user supplied effectiveness and fractions)
000 Choice
000
000
000
000
000 HC CO NOx
000
951
952
953
954
955
956
957
958
959
960
961
962
000
000 Variable CSCRN containing the clean-screening fraction exampted
000 by age for Choices #1-4.
000
000 Choice 1:
000 2:
000 3:
000 4:
000
000 Choice #1 Choice #2 Choice #3 Choice
000 Format
0.
1.
1.
0.
1.
1.
0.
1.
0.
0.
1.
0.
.98
.00
.00
.98
.00
.00
.98
.00
.82
.98
.00
.82
1.
1.
1.
1.
1.
1.
1.
1.
0.
1.
1.
0.
.00
.00
.00
.00
.00
.00
.00
.00
.71
.00
.00
.71
0.
0.
1.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.85
.88
.00
.85
.88
.92
.85
.85
.92
.85
.83
.69
r \U -L LLLCL L-
Choice
Choice
Choice
Choice
Choice
Choice
Choice
Choice
Choice
Choice
Choice
Choice
#1
#1
#1
#2
#2
#2
#3
#3
#3
#4
#4
#4
Pre-1986 model years
1986-1989 model years
1990 and newer model years
Pre-1986 model years
1986-1989 model years
1990 and newer model years
Pre-1986 model years
1986-1989 model years
1990 and newer model years
Pre-1986 model years
1986-1989 model years
1990 and newer model years
0.5/200/1000 HC/CO/NOx cutpoints
0.5/200/1500 HC/CO/NOx cutpoints
0.5/200/2000 HC/CO/NOx cutpoints
0.5/200 HC/CO cutpoints (no NOx cutpoint)
#4
37
-------
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
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.
.614
.553
.492
.431
.370
.309
.248
. 187
.157
.128
.099
.069
.040
.025
.010
.010
.010
.010
.010
.010
.010
.010
.010
.010
.010
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.
.694
.633
.572
.511
.450
.389
.328
.267
.237
.208
. 179
. 149
.120
.105
.090
.075
.075
.075
.075
.075
.075
.075
.075
.075
.075
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.
.724
.663
.602
.541
.480
.419
.358
.297
.267
.238
.209
. 179
.150
.135
.120
.105
.105
.105
.105
.105
.105
.105
.105
.105
.105
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.
.834
.773
.712
.651
.590
.529
.468
.407
.377
.348
.318
.289
.260
.245
.230
.215
.215
.215
.215
.215
.215
.215
.215
.215
.215
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
Age
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
38
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