A system for management evaluation of Virginia's periodic motor vehicle inspection (PMVI) program was developed which is similar to that currently in use by the Virginia Department of State Police, except for changes in the sample size of inspection receipts and a modification of the procedure for sampling inspection receipts. Using the procedure described in this report in previous evaluations and this method should also allow for more suitable statewide inferences concerning Virginia's periodic motor vehicle inspection program. A total of 35,016 approval receipts were sampled and analyzed from the 6,325,485 inspection receipts issued during 1975, and it was found that 22.62% of the vehicles inspected and approved, immediately or after repair at the time of inspection, were defective in some way. Other findings included: (1) The percentages of defective vehicles were similar for passenger vehicles, trucks, and school buses; (2) private inspection stations had a somewhat higher percentage of defective vehicles than unlimited or small exemption stations; (3) headlights, other lights, brakes, and tires were among the items most often reported as defective; (4) for most inspection items there was a slightly greater failure rate for low volume stations than for medium or high volume stations; and (5) there was generally an increase in defects as vehicle age and mileage increased. Limitations noted to result from the design of the current inspection receipt are that: (1) the specific component which is defective and the severity of the defect are not indicated, (2) charges for repairs for individual items are not noted, and (3) there is no assurance of an accurate recording of vehicle mileage. /Author/.
Abstract