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FHWA MSAT Study: US 95 Settlement Agreement

Annual Progress Report, as of June 2011


In June 2005, while an appeal was pending, the Federal Highway Administration (FHWA), the Nevada Department of Transportation (NDOT), and the Sierra Club (SC) settled a court case which had been filed by the SC to prevent the expansion of US 95 in Las Vegas, NV. In the settlement agreement, the FHWA agreed to conduct a study to characterize the emissions of mobile source air toxics (MSAT) and PM2.5 in relation to traffic and meteorological conditions, and measure the dispersion of the emissions from the roadway. This progress report, required by Part 1, Paragraph 5 of the settlement agreement, describes the progress over the past year on the FHWA's fulfillment of its obligations under the agreement.


FHWA and EPA developed a new interagency agreement to conduct the work for the Near Road Collaboration Project in Detroit, Michigan. The funding needed to complete the monitoring in Detroit was $500,000. FHWA contributed $250,000 from STEP and Pooled Fund Program contributions.

Site Operation

Detroit, Michigan

During the past year, data was collected at the Eliza Howell Park along I-96, in Detroit. Due to fiscal constraints, the sampling regime included quarterly MSAT data collection rather than 1 in 12 days as was done in Las Vegas. This plan allowed for four intensive data collection regimes to occur of the course of the past year. The collection of criteria pollutants remained the same as Las Vegas: continuous. At the end of June 2011, all monitoring was complete. The monitoring trailers were packed up and shipped to storage at EPA facilities in Research Triangle Park, North Carolina. Quality assurance and analysis of the Detroit data will begin shortly.

Las Vegas, Nevada

Data collection was complete as of February 2010. During the past year, FHWA has worked extensively with the EPA to analyze the data collected in Las Vegas. Several presentations sharing preliminary results were made at conferences throughout the year. EPA is currently completing a final report for the Near Road Vehicle Emissions Study in Las Vegas.


Over the past year, the FHWA and EPA worked on conducting the monitoring in Michigan, completing quality assurance and analysis of the Las Vegas data, completing a new interagency agreement, and looking for cost saving measures. The agencies expect continued analysis and efforts to present the results in the final report and subsequent national forums and in scientific journals.

Updated: 11/16/2011
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