The National Academies

NCHRP 25-25/Task 108 [Final]

Creating Lookup Tables to Streamline the Determination of Emission Reductions for CMAQ Projects
[ NCHRP 25-25 (Research for the AASHTO Committee on Environment and Sustainability) ]

  Project Data
Funds: $125,000
Research Agency: Louis Berger U.S. Inc.
Principal Investigator: Leo Tidd
Effective Date: 3/1/2018
Completion Date: 6/28/2019

Status: Research is complete.

A compressed file (.zip, 14.7 MB) containing the Simplified Toolkit (.xls) and User Guide (.pdf) may be downloaded HERE. MOVES model specifications, input databases, and output databases used to develop the Toolkit are available HERE (.zip; 82.3 MB; note this is a large file and will take some time to download).  The Final Report, documenting the development of the Tooklit, is available HERE (.pdf, 972 KB).

Note: The Simplified Toolkit is a spreadsheet that is protected from editing and with calculation sheets hidden. An unprotected, fully visible, editable version is available on request from NCHRP. Send file requests to: NCHRP@nas.edu. Please indicate the project number ("NCHRP 25-25/Task 108") in your email request. 


Under the Congestion Mitigation and Air Quality (CMAQ) Program, the Federal Highway Administration (FHWA) distributes funds to states to assist in projects and programs that help reduce vehicle-related emissions in areas with nonattainment or maintenance status. Many types of projects can be considered for CMAQ funding including traffic signal synchronization, ride-sharing programs, and diesel retrofit projects. To obtain CMAQ funds, states must submit an analysis describing the air quality improvement benefits that the project or program will achieve. Analyses submitted in the past to justify a particular project or program have varied widely from a simple qualitative description of the estimated emission reduction benefit to more complex project-specific quantitative analyses. As the time and cost for conducting such analyses can be significant, state DOTs and other project sponsors can benefit from simplified procedures, including the use of lookup tables for typical project types that would significantly reduce the time and cost for analyses by state DOTs while also serving to improve the consistency and accuracy of the estimated emission reductions for FHWA.

This research developed a spreadsheet-based Simplified Toolkit that can be used to calculate emissions reductions for 16 project types, based on minimized and simplified inputs. The NCHRP 25-25 Task 108 Simplified Toolkit is independent of the FHWA CMAQ Emissions Calculator Toolkit (available HERE), but is designed to build upon that resource by providing state DOTs, metropolitan planning organizations (MPOs), and other project sponsors with additional tools to efficiently calculate emissions reductions in accordance with federal requirements.

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