Mobile source air toxics (MSAT) were an issue in a Sierra Club lawsuit on improvements to US 95 in Nevada. The lawsuit settlement agreement included a national study that provided an opportunity to better understand the science and modeling techniques needed to measure the behavior of MSAT.
Over the last few years, the FHWA has expended a good deal of effort to enhance our understanding of mobile source emissions associated with major highway facilities. This research was designed to further the understanding of how mobile source emissions behave, and thus fits well with research being done by others on the effects of particular levels of mobile source emissions.
The FHWA, in conjunction with US EPA and a consortium of State departments of transportation, are studying the concentration and physical behavior of MSAT, mobile source PM 2.5, and other criteria pollutants. In December 2009, the Las Vegas, Nevada data collection phase was completed, and data collection in Detroit, Michigan has begun. These studies will give those involved hands-on knowledge about the dispersion of mobile source emissions and enhance the credibility of State officials when addressing related issues for projects in their State. Ultimately, everyone will benefit from making more informed transportation and environmental decisions.
