Abstract
This article describes an experimental motor vehicle inspection program conducted by the Michigan State Police. The proportion of the vehicle population inspected was systematically varied across counties with 5%, 10%, and 20% levels being used. For the six-month observation period, a modest reduction in vehicle defects, between 5% and 10%, was obtained in the area with the most inspection activity. Driver interviews showed no decrease in public acceptance of the program, despite substantially increased police effort.