Analysis of U.S. Roadside Vehicle Emissions and Tampering Survey Data andEvaluation of Inspection and Maintenance Programs

摘要

Since 1978 the U.S. Environmental Protection Agency has conducted nationwidetampering surveys of the in-use vehicle fleet. The state of California began conducting random roadside surveys in 1985. Both groups discontinued these surveys after their 1992 surveys. This report contains an analysis of data collected from more than 60,000 vehicles stopped at random in the 1985-1990 Environmental Protection Agency Motor Vehicle Tampering Surveys and the 1985-1992 California random roadside surveys. The authors analyzed low-idle carbon monoxide and exhaust hydrocarbon emissions data from vehicles stopped in these surveys, and observed that the portion of the fleet responsible for the majority of emissions as measured by the idle test has declined between 1985 and 1992. The authors analysis has compared I/M program effectiveness for different I/M program types throughout the United States.