Are vehicle emission inspection programs living up to expectations?

摘要

To ensure that the advanced emission control systems installed on modern motor vehicles continue to work properly, motor vehicle inspection and maintenance(I/M)programs are now found in the major cities of many countries around the world. These programs are widely regarded as valuable and even essential to the achievement of air quality objectives, but there have been few ex post audits of these programs. In this paper, we examine the performance of one of the most sophisticated I/M programs, the USEPA's Enhanced I/M Program.