Although the Clean Air Act contributes to cleaner air quality, the greatest success can be found in the control of emissions from on-road mobile sources. According to calculations based on data from the National Air Quality and Emissions Trends Report 1999, published by the U.S. EPA, emissions reductions from motor vehicles account for 84% of the total emissions reductions of the 6 criteria pollutants since 1970. The automotive, fuels, highway, and transit communities have managed to achieve this success in cleaning up the Nation's air with the help of tighter EPA emissions standards and fuel requirements, while concurrently meeting increasing demands for improved mobility and safety. This article discusses the trend towards reduced emissions in the U.S. and how efforts from the Federal to the local levels will help continue the air quality gains seen to date.
Abstract