Transportation Conformity - Project Analysis

A localized analysis of traffic and air quality impacts (i.e., hot-spot analysis) is performed for individual projects that are:

Regionally significant projects included in a conforming TIP/RTP that meet certain criteria
Newly conceived projects unable to be included in the current TIP/RTP
Started after the three-year time limit lapses for a project found in conformity

Carbon Monoxide (CO) analysis is required for:

Projects at sites which are identified as possible violation sites
Any projects affecting one or more of the top three intersections in terms of traffic volume
Worst level of service
Project affecting intersections at Level of Service D, E, or F

Particulate Matter less than either 2.5 or 10 microns in diameter (PM_2.5 and PM₁₀) analysis is required for:

New or expanded highway projects that have a significant number of or significant increase in Diesel vehicles
Projects affecting intersections at Level of Service D, E, or F because of increased traffic volumes from a significant number of Diesel vehicles
New or expanded bus and rail terminals which increase the number of Diesel vehicles at a single location
Expanded bus and rail terminals and transfer points that significantly increase the number of Diesel vehicles congregating at a single location and
Projects in or affecting locations, areas, or categories of sites which are in the PM_2.5 and PM₁₀ applicable implementation plans or implementation plan submission as sites of violation or possible violation.

The EPA’s website - Project-Level Conformity and Hot-Spot Analyses - contains the policy guidance, technical guidance, and modeling resources that states and local agencies can use to conduct project-level conformity analyses, including PM2.5 and PM10 and CO hot-spot analyses

The PM hot-spot guidance describes how to use the on-road emissions model to conduct hot-spot analyses for new highway and transit projects that involve significant diesel emissions. It also outlines how to apply the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) for PM hot-spot analyses. The guidance has been updated to reflect the latest on-road emissions model (MOVES3).

The CO hot-spot guidance describes how to use the on-road emissions model to estimate CO emissions from transportation projects, including roadway intersections, highways, transit projects, parking lots, and intermodal terminals. Like the PM hot-spot guidance, the CO hot-spot guidance has also been updated to reflect MOVES3.

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