Models & Methodologies

Many different software programs and other modeling techniques are utilized when conducting transportation conformity determinations and related activities. For instance, various EPA models can be used to predict emissions of different pollutants from on-road and nonroad sources, to calculate delays and queues that occur at signalized intersections, and to provide estimates on how commuter benefits can impact vehicle emissions, as well as fuel use and costs. In addition, FHWA has developed some tools based on these models to make emission inventory calculations in rural or small urban areas and to provide user-friendly interfaces to some of the models

All Documents

MOVES2010b Questions and Answers (PDF) (April 2012) - This document highlights the differences between MOVES2010b and earlier versions of MOVES and explains EPA policy on using MOVES2010b in State Implementation Plans and Transportation Conformity Analyses.
Policy Guidance on the Use of MOVES2010 and Subsequent Minor Revisions for State Implementation Plan Development, Transportation Conformity, and Other Purposes (PDF) (April 2012) - This document describes how and when to use the MOVES2010 (and subsequent minor revisions like MOVES2010b) for SIP development, transportation conformity, general conformity, and other purposes.
Using MOVES to Prepare Emission Inventories in State Implementation Plans and Transportation Conformity: Technical Guidance for MOVES2010, 2010a and 2010b (PDF) (April 2012) - This document provides guidance on appropriate input assumptions and sources of data for the use of MOVES2010, MOVES2010a, and MOVES2010b in SIP submissions and regional emissions analyses for transportation conformity purposes.
EPA/DOT Training for Quantitative PM Hot-Spot Analyses - EPA and DOT have developed a three-day training course on implementing EPA's "Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas. This technical, hands-on course is geared toward state and local agency staff and will focus on using emission models (including EPA's MOVES model) and air quality models (AERMOD and CAL3QHCR) for quantitative PM hot-spot analyses.
Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas (EPA, December 2010) - Guidance for modeling the local air quality impacts of certain transportation projects on the PM2.5 and PM10 national ambient air quality standards (NAAQS). This guidance is to be used by state and local agencies to conduct quantitative PM “hot-spot analyses” for new highway and transit projects that involve significant diesel emissions.
Main document only
Appendices only
Fact Sheet (HTML) or (PDF)
FHWA Air Quality Resource Center Training
Using MOVES in Project-Level Carbon Monoxide Analyses (EPA, December 2010) - This guidance describes how to use the MOVES emissions model to estimate CO emissions from transportation projects, including roadway intersections, highways, transit projects, parking lots and intermodal terminals.
Federal Register Notice of Availability: Official Release of the MOVES2010a and EMFAC2007 Motor Vehicle Emissions Models for Transportation Conformity Hot-Spot Analyses and Availability of Modeling Guidance (December 2010) – This notice approves MOVES2010a for PM and CO hot-spot analyses (and EMFAC2007 for PM hot-spot analyses in California) with a 2-year conformity grace period. EPA also announced the availability of its final PM hot-spot guidance and CO project-level MOVES guidance.
- Questions and Answers
Modifying Link-Level Emissions Modeling Procedures for Applications within the MOVES Framework (September 2010) - Prepared by Eastern Research Group, Inc. for FHWA, the primary goal of the study was to ease the transition to the MOVES model by providing both a road map for developing updated emissions inventories, as well as an analysis of the likely impacts of the transition on the emissions inventories themselves.
MOVES2010 Mobile Source Emissions Model: Questions and Answers (PDF) (December 2009) - This document describes the model and provides general information for model use.
Federal Register Notice of Availability: Official Release of MOVES2010 Motor Vehicle Emissions Model for Emissions Inventories in SIPs and Transportation Conformity (March 2010) - This notice approves the use of MOVES2010 in official SIP submissions and starts a two-year grace period before MOVES2010 is required to be used in new regional emissions analyses for transportation conformity determinations outside of California.
Official Release of EMFAC2007 Motor Vehicle Emission Factor Model for Use in the State of California (January 2008) - Federal Register notice announcing the availability of the latest version of the California EMFAC model for use in state implementation plan (SIP) development in California
Policy Guidance on Use of November 2006 Update to AP-42 for Re-entrained Road Dust for SIP Development and Transportation Conformity (August 2007) - EPA guidance on changes made to the AP-42 methods for road dust and how and when to use them in PM2.5 SIPs and transportation conformity determinations. This guidance supersedes the AP-42 portions of EPA's February 2004 guidance, which addressed both MOBILE6.2 and AP-42. The portions of the February 2004 guidance addressing MOBILE6.2 remain in effect.
Diesel Retrofits: Quantifying and Using Their Benefits in SIPs and Conformity - Guidance for State and Local Air and Transportation Agencies (June 2006) - EPA guidance on quantifying and using emission reductions from highway and nonroad diesel vehicles, engines, and equipment that have been retrofitted. It discusses how emission reductions from diesel retrofit projects can be used in a SIP and in transportation conformity and general conformity determinations.
Guidance for Creating Annual On-Road Mobile Source Emission Inventories for PM2.5 Nonattainment Areas for Use in SIPs and Conformity (August 2005) - EPA guidance on preparation of annual inventories for PM2.5 SIPs or regional conformity analyses by state and local agencies. It also addresses the possible use of the National Mobile Inventory Model (NMIM) in SIPs and conformity analyses.
MOBILE6 Implementation Experience (June 2005) - FHWA, in conjunction with the Association of Metropolitan Planning Organizations (AMPO) Air Quality Subcommittee, worked with a group of MPOs to document their experience in applying MOBILE6 in the conformity process. Thus purpose of the study is to provide an understanding of what steps these organizations took to prepare for use of the new MOBILE model and to identify potential training and technical assistance needs. Specifically, this study documents how MPOs are implementing MOBILE6, what data are being collected locally, and how data are being collected and identifies implementation issues that arose during the transition to MOBILE6.
Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation (August 2004) - EPA guidance on appropriate input assumptions and sources of data for the use of MOBILE6.2 in SIP and conformity related submissions
Implications of the Implementation of the MOBILE6 Emissions Factor Model on Project-Level Impact Analyses Using the CAL3QHC Dispersion Model (August 2004) - Prepared by ICF Consulting for FHWA, this report discusses how revisions to the MOBILE model affect the estimation of localized CO concentrations, including problems and difficulties in the interaction of MOBILE6 with CAL3QHC, as well as recommendations for addressing these issues. In addition, this report discusses how the implementation of MOBILE6 impacts screening assessment procedures.
Official Release of the MOBILE6.2 Motor Vehicle Emissions Factor Model and the December 2003 AP-42 Methods for Re-Entrained Road Dust (May 2004) - Federal Register Notice announcing the availability of the MOBILE6.2 motor vehicle emissions factor model for official use in particulate matter (PM10 and PM2.5) SIPs and transportation conformity determinations outside of California
Screening Procedures for Project-Level Hotspot Analysis Screening Procedures for Project-Level Hotspot Analysis (April 2004) - FHWA Resource Center paper that provides a summary of project-level CO screening procedures developed and adopted by transportation agencies throughout the nation, highlights several innovative practices, and offers recommendations for developing refined screening protocols
Policy Guidance on the Use of MOBILE6.2 and the December 2003 AP-42 Method for Re-Entrained Road Dust for SIP Development and Transportation Conformity (February 2004) - EPA guidance that describes how and when to use MOBILE 6.2 and the December 2003 AP-42 method in SIP development and transportation conformity determinations
Official Release of the MOBILE6 Motor Vehicle Emissions Factor Model (January 2002) - Federal Register Notice announcing the availability of EPA's MOBILE6 motor vehicle emissions factor model for official use outside of California
Policy Guidance on the Use of MOBILE6 for SIP Development and Transportation Conformity (January 2002) - EPA guidance on how and when to use MOBILE 6.2 and the December 2003 Update to AP-42 in SIP development and transportation conformity determinations
EPA's MOVES (Motor Vehicle Emission Simulator) Website - EPA website for its MOVES software, as well as related presentations and training resources
EMIT Website - Information about the EMIT model from the FHWA Resource Center
COMMUTER Programs - EPA website for its COMMUTER Software, as well as related files
Appendix W to Part 51 - Guideline on Air Quality Models
Off-Model Air Quality Analysis: A Compendium of Practice - FHWA Resource Center paper about Off-Model methods (analyses performed without the specific use of a Travel Demand Model) being successfuly used in the South
EPA's MOBILE6 Vehicle Emission Modeling Software - EPA website for its MOBILE6 Vehicle Emission Modeling Software, as well as related presentations and training resources
EPA/FHWA MOVES Training - EPA and FHWA will be offering MOVES training in a number of different formats. Course descriptions and availability are listed on EPA's website.
EMFAC Software - CARB's website for its EMFAC software, as well as related presentations and training resources
Sensitivity Analysis of MOBILE6 Motor Vehicle Emission Factor Model or PDF - FHWA Resource Center paper that provides a basic evaluation of the MOBILE6 model behavior under various conditions
National Mobile Inventory Model (NMIM) - EPA's website for its NMIM software
MOVES Research - EPA reports provided on its MOVES website
User Friendly Version of CAL3QHC - The FHWA Resource Center is designing a new, easy-to-use interface for two air quality models: EPA's California Line Source Dispersion Model (CALINE3) for freeways and the CAL3QHC model for signalized intersections. With the new interface, the models will run on the Microsoft Windows® operating system and will include interactive graphical forms for entering data.
Microscale and Regional Modeling and Emission Models - Abstracts for products produced by or for the Federal Highway Administration.

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