Best Practices for Mitigation Measures for Air Quality for Transportation Projects

Focus Area

Air Quality


Air Quality






1-2 years

Research Idea Scope

The proposed study would develop a practical guide for
(or compendium of) mitigation measures for air quality for typical highway and
transit projects that, ultimately, may serve as the basis for the future
development of a comprehensive set of best practices. A critical objective of
the proposed study would be developing procedures or approaches to modeling of
mitigation measures that would be acceptable for credit in project-level air
quality analyses completed to meet the requirements of the federal
transportation conformity rule (as well as for purposes of NEPA). Close
coordination with both the US DOT and EPA will be needed for this purpose.


Measures to be assessed include those identified in
federal guidance for project-level air quality analyses as well as any
additional or innovative measures identified in the course of the study.
Measures applicable for the construction phases of projects should also be
considered. Costs and cost-effectiveness for the measures should also be
determined for all pollutants for which measures are proposed, with
consideration for measures implemented singly or in combination.



This topic was discussed at the 2013 annual meeting of
the AASHTO Subcommittee on Environment (SCOE), following proposals at the 2012
annual meeting of the Transportation Research Board ADC20 Project-Level Air
Quality Analysis Subcommittee. 
Mitigation measures were also included in proposals for best practices
presented at the 2012 Annual SCOE meeting and the 2013 Transportation Research
Board ADC20 Project-Level Air Quality Analysis Subcommittee meeting, and
included in recommendations for future research in the December 2012 AASHTO Air
Quality Community of Practice report on “Project-Level Quantitative Hot-spot
Analyses for PM2.5 and PM10 – State-of-the-Practice”. Recommendations related
to construction emissions and modeling were derived from the 2013
State-of-the-Practice report on the subject from the AASHTO Air Quality
Community of Practice.

Urgency and Payoff

With the recent introduction by EPA of new models and
guidance for project-level air quality analyses for transportation, state DOTs
and other project-sponsors would benefit significantly from timely research
leading to improvements in the process for identifying appropriate mitigation
measures for a given highway (including intermodal) or transit project based on
project type, costs, cost-effectiveness, the potential for credit (acceptable
as appropriate to EPA and the US DOT) in project-level air quality modeling,
and other key considerations determined in the study as appropriate.

Suggested By

Christopher Voigt Virginia DOT 804.371.6764

[email protected]