United States
                    Environmental Protection
                    Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
                    Research and Development
EPA/600/SR-93/214   January 1994
&EPA       Project Summary

                    Conceptual  Designs for  a
                    New Highway  Vehicle
                    Emissions  Estimation
                    Methodology
                    John T. Ripberger
                     This report discusses conceptual de-
                    signs from  six contractors for a new
                    highway vehicle emissions estimation
                    methodology and summarizes the con-
                    tractors' recommendations for improv-
                    ing the emissions and activity factors
                    in the emissions estimation  process.
                    The complete reports are included as
                    appendices. EPA asked these contrac-
                    tors to assist in developing ideas for a
                    future improved methodology to esti-
                    mate  highway vehicle emissions. They
                    were  selected because of their experi-
                    ence  in working  with mobile source
                    emissions inventories.
                     In general, the contractors suggest
                    developing  new modules  within  the
                    emission estimation process to provide
                    users with  more detailed information
                    on  the causes of vehicle  emissions.
                    The essence of these suggestions is
                    the need for more comprehensive inte-
                    gration of data between the transporta-
                    tion planning model and  the emission
                    factor model. The reports  reinforced
                    comments voiced by other experts for
                    modal data and more responsive trans-
                    portation models, although they did not
                    identify  totally new concepts not al-
                    ready being considered by  EPA re-
                    search programs.
                     This Project Summary was developed
                    by  EPA's Air and Energy Engineering
                    Research Laboratory, Research  Tri-
                    angle Park,  NC, to announce key find-
                    ings of the research project that is fully
                    documented in a separate report of the
 same title (see Project Report ordering
 information at back).

 Project Overview
  In April 1991, six tasks were awarded
 to look for new concepts that could poten-
 tially provide improved emission inventory
 estimates from highway vehicles in 5-10
 years. Contractors were asked to submit
 their ideas for a new highway vehicle emis-
 sions estimation methodology. The request
 to the contractors was to determine  if,
 because of changes in vehicle technolo-
 gies, transportation analysis tools, and sci-
 entific understandings, adoption of new
 concepts could provide significant advan-
 tages over  existing methodologies. This
 project was a follow-on to the two high-
 way vehicle workshops held in the sum-
 mer of  1990 to solicit recommendations
 from emission inventory experts. The con-
 tractors (Alliance Technologies Corp.,
 Desert Research Institute, E. H. Pechan
 & Associates, Inc., Radian Corp., Sierra
 Research, Inc., and Systems Applications
 International) were selected because  of
 their experience in using and developing
 mobile  source emission  inventories for
 EPA and California. E. H. Pechan  & As-
 sociates teamed with COMSIS Corpora-
 tion to address transport modeling recom-
 mendations. Ground rules for the study
 were that: 1) emission inventory estimates
 are used by EPA and states in models to
 determine the effectiveness of various con-
 trol strategies for achieving air quality stan-
 dards; 2) the methods now available for
                                                                   Printed on Recycled Paper

-------
estimating  emissions  from  highway ve-
hicles will not be adequate for the  new
fuels, technologies, and transportation con-
trol methods  available in 5 to 10 years;
and 3) this project is intended to begin the
process of  looking for an optimum meth-
odology for estimating emissions and en-
suring that the estimates meet future U.S.
needs. The results  of this  effort should
help produce better methods for estimat-
ing emissions from highway vehicles. The
time frame for implementing any  new con-
cepts is 5 - 10 years.
  This report summarizes the conceptual
designs received  in 1991  from six  con-
tractors.  Their complete  reports are in-
cluded as appendices.  In general, the con-
tractors' reports suggest developing new
modules  within the emission estimation
process to provide users with more de-
tailed information on the causes of vehicle
comprehensive integration of data between
the transportation planning model and the
emission factor model. To present the con-
tractors' recommendations clearly and  to
avoid redundancy, this  report combines
their concepts and organizes them ac-
cording to topic,  rather than simply sum-
marizing each contractor's conceptual de-
sign separately. First, concepts on improv-
ing emission factors are considered, fol-
lowed by recommendations  for improving
activity factors, and ideas for organizing
and  coordinating the new emission and
transportation models.
  As EPA develops its research program
to prepare emission inventory models for
the future, it is attempting to ensure that
no  promising  new concepts are  over-
looked.  This  effort was  to solicit  ideas
from contractors experienced in estimat-
ing emissions from highway vehicles. For
the most part, the  reports did not identify
any totally new concepts not already be-
ing considered by EPA research programs.
Most of the ideas were linked to existing
procedures,  requiring much costly data
collection  concerning vehicle emissions
and operations on highway networks. The
reports  reinforced  comments voiced by
other  experts for modal  data and  more
responsive transportation models.

   'U.S.Government Printing Office: 1994550-067/80135
 J. T.  Ripberger is a Participant in the Earth Team Soil Conservation Service
    Volunteer Program assisting the U.S. EPA.
 Carl T. Ripberger is the EPA Project Officer (see below)
 The complete report, entitled "Conceptual Designs for a New Highway Vehicle
    Emissions Estimation Methodology," (Order No.  PB94-120 128/AS; Cost:
    $36.50, subject to change) will be available only from:
          National Technical Information Service
          5285 Port Royal Road
          Springfield, VA 22161
          Telephone: 703-487-4650
 The EPA Author and Project Officer can be contacted at:
          Air and Energy Engineering Research Laboratory
          U.S. Environmental Protection Agency
          Research Triangle Park, NC 27711
 United States
 Environmental Protection Agency
 Center for Environmental Research Information
 Cincinnati, OH 45268

 Official Business
 Penalty for Private Use
 $300
                                                         BULK RATE
                                                   POSTAGE & FEES PAID
                                                             EPA
                                                       PERMIT No. G-35
 EPA/600/SR-93/214

-------