Guidance for Transportation Modelers for Generating Traffic and Activity Data for Project-Level Air Quality Analyses

Focus Area

Air Quality


Air Quality




Under $99k


Under 1 year

Research Idea Scope

The recently completed NCHRP 08-83 study (see excerpt below) on “Analytical Travel Forecasting Approaches for Project-Level Planning and Design” addressed project-level transportation modeling in detail but only addressed air quality in a very limited manner. This proposal is to develop a supplement to NCHRP 08-83 that would provide appropriate background and guidance for transportation modeling professionals for the generation of traffic and activity data for project-level air quality analyses. For background, traffic and activity data and forecasts have always been important inputs for project-level air quality modeling and analyses for carbon monoxide. Their role however was made much more critical with the recent advent of new models and guidance by EPA for modeling particulate matter (PM), for which background concentrations are typically much higher and passing the air quality tests therefore much more challenging. Practical guidance written by and for transportation modeling professionals is needed to support these analyses. Reference: NCHRP 08-83 [Completed] Analytical Travel Forecasting Approaches for Project-Level Planning and Design The objective of this research was to develop a guidebook describing methods, data sources, and procedures for producing travel forecasts for highway project-level analysis. The guidebook evaluates and expands on currently used methods and tools to include appropriate data or information sources and system-level methods (ranging from readily available practices to advanced practices) to address a variety of project development purposes, needs, and impacts. The guidebook is intended to be used by transportation planning, operations, and project development staff to better support planning, design, and operations recommendations. Status: The project is complete and the final guidebook will be published as NCHRP Report 765. Spreadsheet tools will be available as NCHRP CD-ROM CD-143.

Urgency and Payoff

Traffic forecasts may be a focus of challenges to NEPA documents, so state DOTs and other project sponsors would benefit from improved quality control and reliability for those forecasts. Transportation modelers in general may benefit significantly from having practical guidance developed by experts in the specialty topic area of modeling for air quality.

Suggested By

Christopher Voigt Virginia DOT 804.371.6764

[email protected]