Congestion Mitigation and Air Quality Improvement (CMAQ) Program
The Congestion Mitigation and Air Quality (CMAQ) Improvement Program was established by the 1991 Federal Intermodal Surface Transportation Efficiency Act (ISTEA) reauthorized with the passage of Transportation Equity Act for the 21st Century (TEA-21), and superseded by the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). Funds are directed to transportation projects and programs which contribute to the attainment or maintenance of National Ambient Air Quality Standards (NAAQS) in nonattainment or air quality maintenance areas for ozone, carbon monoxide, or particulate matter (PM) under provisions in the Clean Air Act (Title 42, United States Code).
The first and foremost priority for CMAQ funds should be cost-effective clean air strategies that implement the transportation and motor vehicle provisions of the State Implementation Plan (SIP). For this reason, cost-effectiveness should be the primary criterion in CMAQ project selection. This will assure that public health benefits of the CMAQ program are maximized and continuation of the program is justified.
The Methods to Find the Cost-Effectiveness of Funding Air Quality Projects document includes methods and examples for evaluating the emission reductions and cost-effectiveness of CMAQ projects and motor vehicle registration fee projects.
Automated Tool to Find the Cost-Effectiveness of Funding Air Quality Projects
The following tools enable staff and decision-makers to quantify the cost-effectiveness of proposed projects in terms of cost per pound (or ton) of pollutants reduced. These tools are used to evaluate projects and to report on both the CMAQ and the Motor Vehicle Registration Fee Program.
This automated Access database program includes methods for the following project categories: cleaner on- and off-road vehicle purchases and re-powers; cleaner street sweepers; new bus service operations; vanpool and shuttle service; traffic signal coordination; bicycle facilities; telecommunications; and ridesharing and pedestrian facilities.
- Automated Cost-effectiveness Calculation Tool (To download, use the Firefox web browser)
Emission Factor Tables
The latest emission factor tables below are to be applied in the Automated Cost-effectiveness Calculation Tool.
- Emission Factor Tables (December 2022)
The Federal Highway Administration (FHWA), in cooperation with the Federal Transit Administration, has also developed cost-effectiveness analysis methods for various types of CMAQ projects. Staff may also apply these analysis methods developed by FHWA to estimate the cost-effectiveness of CMAQ projects when appropriate:
If you have any questions on the CMAQ program, please send an email to CMAQ@arb.ca.gov