Inspection/Maintenance (I/M) is one of the transportation control strategies available to state planners. Although I/M is needed in over 25 air quality control regions (AQCRS), it has, to date, been effectively implemented in only a small subset of these regions. At the present time, an effective I/M program has not been implemented in a high altitude region. This report presents a thorough analysis of data collected at high altitude. The data were not collected in a real life I/M program; they are laboratory data. As such, they can be compared with laboratory data taken at low altitude and, in some subject areas, they can extend the general understanding of the costs and effectiveness of maintenance programs at both high and low altitude. The prime analysis objectives of this study were threefold: to estimate the effectiveness of I/M, to evaluate the correlation between the Federal Test Procedure (FTP) and various short inspection tests, and to examine any relationships which exist between emissions, engine condition, and vehicle usage.

"EPA 460-3-77-018." "September 1977." Cover title. Includes bibliographical references.