University of California Transportation Center

Reducing emissions of pollutants from cars requires that new vehicles be designed and built to pollute less, and also requires some ongoing inspection and maintenance programme to ensure that a vehicle's operation conforms to those design standards. This paper focuses on these programmes, commonly called Smog Check programmes. The most extensive and well-studied Smog Check programme in the United States is in California. Though that state is not typical in all respects, examining its experience is instructive.