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SAFETEA-LU Evaluation and Assessment Phase I

Appendix B. Emissions Factors and Assumptions Used in Emissions Reduction Cost-Effectiveness Calculations

Table B-1. Major Input Parameters for MOBILE6.2 Emissions Factor Modeling.
Parameter or Variable Values or Sources
Vehicle Fleet and Activity Inputs
VMT mix EPA national average (default)
Mileage accrual rates EPA national average (default)
Vehicle model year (registration) distribution EPA national average (default)
Diesel sales fractions EPA national average (default)
Soak time distribution EPA national average (default), or All soak times >720 minutes (corresponds to 100% cold starts).
Starts per day distribution EPA national average (default), or Zero starts per day (for running emissions only)
Region Low altitude
Vehicle speeds Varied 2.5 mph and 3-65 mph by integers, with single average speed per scenario.
Roadway facility (functional classes) Arterial (allows use of specific average speeds)
Seasonal/Meteorological Inputs
Month of evaluation July
Temperatures for all pollutants
  • Minimum:68.0° F
  • Maximum:94.0° F

(Representative summer temperatures only. Actual source for these values is high-ozone-day data from Boston, MA nonattainment area SIP.)

Absolute humidity MOBILE6.2 default
Fuel Inputs
ASTM Class MOBILE6.2 default
Oxygenated fuels No (MOBILE6.2 default)
Reformulated gasoline No (MOBILE6.2 default)
Gasoline RVP 8.7 psi (Representative summer RVP only. Actual source for this value is Philadelphia, PA nonattainment area SIP.)
Diesel fuel sulfur content 15 ppm
State Program Inputs
Inspection/Maintenance (I/M) Program No program (MOBILE6.2 default)
Low Emitting Vehicle (LEV) Program No program (MOBILE6.2 default)
Anti-tampering program (ATP) No program (MOBILE6.2 default)
Stage II refueling controls Not modeled (NO REFUELING command used).
Other Inputs
Particulate matter emissions parameters EPA national average (default)
All other inputs EPA national average (default)
  1. Table of Contents
  2. Executive Summary
  3. Section One
  4. Section Two
  5. Section Three
  6. Section Four
  7. Appendix A
  8. Appendix B
  9. Appendix C
  10. Appendix D
Updated: 3/31/2014
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