Best Practices for Streamlining Project-Level Analyses for Air Quality

Focus Area

Air Quality


Air Quality






2-3 years

Research Idea Scope

Air quality project-level analyses (PLAs) that state DOTs are required to prepare for purposes of NEPA and the EPA transportation conformity rule have become more complicated, time-consuming and costly in the past decade or so. Previously, PLAs focused on CO, which could be modeled with relative confidence using the simple-to-apply CAL3QHC model. However, more complicated modeling requirements have since been introduced, including those for PM (2010), which involves the use of the much more complicated dispersion model AERMOD, and ongoing updates to guidance for mobile source air toxic analyses. Indirect effects and cumulative impact analyses are also now being conducted for air quality. This study would review current practices and develop recommendations for best practices with a focus on streamlining.

Urgency and Payoff

State DOTs would benefit from a set of recommended best practices that would help minimize the time and cost for preparing PLAs while not increasing risk. It would be timely given that much more complicated modeling requirements were introduced in 2010, and experience has been gained in responding to those requirements, but a systematic assessment has not yet been conducted to determine best practices in response to those new requirements.

Suggested By

Christopher Voigt Virginia DOT 804.371.6764

[email protected]