Policy & Guidance
- Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas (EPA, November 2013) - 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. Update of November 2013: This guidance was originally released in December 2010, and Sections 5, 7.6, and 9.4 have been updated to reflect EMFAC2011 and EPA's 2012 PM NAAQS final rule. The November 2013 guidance supersedes the December 2010 guidance.
- Guidance for Transportation Conformity Implementation in Multi-Jurisdictional Nonattainment and Maintenance Areas (EPA, July 2012) This document updates and supersedes EPA's 2004 "Multi-jurisdictional guidance." It describes how transportation conformity determinations are done in areas where multiple metropolitan planning organizations (MPOs), states and/or other agencies have jurisdiction in a nonattainment or maintenance area. The revised guidance is consistent with the Transportation Conformity Restructuring Rule and applies to any current and future NAAQS, including the 2008 ozone NAAQS.
- 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.
- Using the MOVES and EMFAC Emissions Models in NEPA Evaluations (EPA, February 2011) - This memo describes how EPA's emissions models MOVES and EMFAC can be incorporated into the NEPA process.
- 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.
- Guidance for the Use of Latest Planning Assumptions in Transportation Conformity Determinations (or PDF, 308 KB) (December 2008) - Joint USDOT and EPA guidance to clarify expectations for implementing the transportation conformity rule's latest planning assumptions requirements
- 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.
- Transportation Conformity Guidance for Qualitative Hot-Spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas (March 2006) - Memorandum from FHWA and EPA on how to perform qualitative hot-spot analyses in PM2.5 and PM10 nonattainment and maintenance areas, as required by the March 10, 2006, final transportation conformity rule.
- Interim Guidance for Implementing the Transportation Conformity Provisions in SAFETEA-LU (February 2006) - Memorandum from FHWA, FTA, and EPA concerning guidance on implementing the transportation conformity-related provisions contained in SAFETEA-LU - this interim guidance pertained to the time period before the federal transportation conformity rule was revised
- Guidance for Determining the "Attainment Years" for Transportation Conformity in New 8-Hour Ozone and PM2.5 Nonattainment Areas (March 2005) - EPA guidance for 8-hour ozone and PM2.5 nonattainment areas in selecting attainment dates for use in transportation conformity determinations both before and after SIPs are submitted. It also describes some flexibilities that are available to areas using interim emission or budget tests in choosing which years to perform a regional emissions analysis.
- Conformity Information to Inform PM-2.5 Designations (October 2004) - EPA guidance on the transportation conformity burden associated with designating areas for the PM2.5 air quality standard
- Transportation Conformity in Complex Areas (August 2004) - EPA guidance to address conformity implementation in multi-jurisdictional nonattainment and maintenance areas for existing and new air quality standards, as well as results of an FHWA study of current transportation practices in these areas.
- Information: Limited Maintenance Plans (September 2001) - Memorandum from EPA detailing instances when moderate PM10 nonattinment areas can be redesignated to attainment with a streamlined maintenance plan.
- Use of Latest Planning Assumptions in Conformity Determinations - January 18, 2001 (January 2001) - Memorandum from FHWA and FTA providing clarification that the conformity determination must be based on the most recent planning assumptions - this guidance was superceded by new guidance in December 2008