Emissions inspection and maintenance (I/M) programs subject vehicles to periodic inspections of their emission control systems. Despite widespread use of these programs in air-quality management, policy makers and the public have found a number of problems associated with them. Prominent among these issues is the perception that emissions benefits and other impacts of I/M programs have not been evaluated adequately. Evaluating Vehicle Emissions Inspection and Maintenance Programs assesses the effectiveness of these programs for reducing mobile source emissions. In this report, the committee evaluates the differences in the characteristics of motor vehicle emissions in areas with and without I/M programs, identifies criteria and methodologies for their evaluation, and recommends improvements to the programs. Most useful of all, this book will help summarize the observed benefits of these programs and how they can be redirected in the future to increase their effectiveness.

Every year roughly 100,000 fatal and injury crashes occur in the United States involving large trucks and buses. The Federal Motor Carrier Safety Administration (FMCSA) in the U.S. Department of Transportation works to reduce crashes, injuries, and fatalities involving large trucks and buses. FMCSA uses information that is collected on the frequency of approximately 900 different violations of safety regulations discovered during (mainly) roadside inspections to assess motor carriers' compliance with Federal Motor Carrier Safety Regulations, as well as to evaluate their compliance in comparison with their peers. Through use of this information, FMCSA's Safety Measurement System (SMS) identifies carriers to receive its available interventions in order to reduce the risk of crashes across all carriers. Improving Motor Carrier Safety Measurement examines the effectiveness of the use of the percentile ranks produced by SMS for identifying high-risk carriers, and if not, what alternatives might be preferred. In addition, this report evaluates the accuracy and sufficiency of the data used by SMS, to assess whether other approaches to identifying unsafe carriers would identify high-risk carriers more effectively, and to reflect on how members of the public use the SMS and what effect making the SMS information public has had on reducing crashes.

Considers implementing a national automobile emission standard. Feb. 13 and 14 hearings were held in Los Angeles, Calif.; Feb. 20 and 21 hearings were held in Detroit, Mich., pt.1; Considers S. 780, the Air Quality Act of 1967, to establish a program of Federal air quality standards and assistance to state programs focusing on controlling automobile exhaust emissions. Apr. 3 hearing was held in Denver, Colo., and Apr. 4 hearing in St. Louis, Mo. pt. 2; Considers status of ambient air quality criteria. Includes the following reports. a. National Center for Air Pollution Control, "Current Status Report; State and Local Pollution Control Programs" May, 1967 (p. 1160-1283). b. New York City Council, "Air Pollution in New York City" June, 1965 (p. 1495-1568). c. New York City Council, "Blueprint for Cleaner Air" Dec. 1965 (p. 1569-1624), pt.3; to provide efficient air pollution controls for industry and autos, pt.3; Continuation of hearings considering S. 780, to provide efficient air pollution controls for industry and autos, pt.4.