1

MEMORANDUM

Date: February 15, 2012

Subject: Summary of EPA Regional Office Survey about MOVES Transition for Regional 

Conformity Analyses 

From: Meg Patulski, State Measures and Transportation Planning Center, OTAQ

To: Docket EPA-HQ-OAR-2011-0393

In February 2011, EPA’s Office of Transportation and Air Quality (OTAQ) surveyed its 

EPA Regional Offices to determine the status of state and local agency transition to using 

MOVES in regional conformity analyses. This survey was based on a cursory review of existing 

information already available to the EPA Regions including: 

 The status of discussions about the transition to MOVES through the interagency

consultation process, 

 Whether state and local agencies had gained competency and technical expertise in using 

MOVES for either regional conformity analyses or SIP development, and

 Any possible or anticipated revisions to SIP motor vehicle emissions budgets with 

MOVES. 

The information below summarizes the results of OTAQ’s informal survey.

Overview:

In February 2011, there were approximately 100 nonattainment and maintenance areas 

for the 1997 ozone national ambient air quality standard (NAAQS) and 37 nonattainment areas 

for the 1997 annual PM2.5 NAAQS in states outside of California.1 Under the transportation 

conformity rule at that time, these areas were required to begin using MOVES in regional 

conformity analyses when the MOVES grace period ended in March 2012. Many of these areas 

had already submitted state implementation plans (SIPs) based on MOBILE6.2. EPA had 

already approved maintenance plans for nearly 70 ozone areas. 

 

1

Please note that EPA had already released guidance indicating that nonattainment areas for the 2006 PM2.5

NAAQS should prepare their SIPs using MOVES. In addition, all areas in California were excluded from this 

survey because they use the EMFAC model to calculate on-road mobile source emissions instead of EPA’s 

MOBILE or MOVES model.
2

1997 Ozone NAAQS Areas:

Based on the results of the informal survey, approximately 80% of ozone areas (80 areas) 

needed additional transition time for regional conformity analyses with MOVES. The remaining 

ozone areas (about 20 areas) involved miscellaneous situations, e.g., isolated rural areas that did 

not anticipate making a conformity determination in the near future.

1997 Annual PM2.5 NAAQS Areas:

Based on the results of the informal survey, approximately 81% of PM2.5 areas (30 areas) 

needed additional transition time for regional conformity analyses with MOVES. The remaining 

PM2.5 areas involved miscellaneous situations, e.g., EPA had previously found regional 

emissions to be insignificant so a regional conformity analyses was no longer required. 

Additional Details:

The majority of ozone and PM2.5 areas had not yet begun to use MOVES for conformity 

purposes for several reasons. Start-up issues included: building technical capacity in-house at 

an MPO or obtaining staff elsewhere (e.g., from state DOT); other constraints on emissions 

modeling staff; and data collection and reformatting MOBILE data for use in MOVES. Replanning issues included having the necessary time (after a MOVES regional conformity analysis 

was completed) to either update the transportation plan and transportation improvement program 

and/or revise an existing approved or adequate MOBILE-based SIP motor vehicle emissions 

budget with MOVES. Many Regions believed it would take at least a year (and sometimes 

longer) for states to update any SIP budgets with MOVES, once MOVES was used for regional 

conformity analyses. States have different processes for developing SIPs depending on state law 

and other factors (e.g., accommodating interagency consultation and public involvement).