Abstract
Following the discontinuance of mandatory periodic motor vehicle inspection, a study was undertaken to compare the mechanical condition of vehicles onder a periodic inspection program to that of vehicles without such a program. To accomplish this objective, a "before and after" study was designed to assess any differences in the mechanical condition of vehicle subsequent to the abolition of Idaho's mandatory inspection law. It was concluded that Idaho's vehicles were in better condition under their MPMVI program than they are now without such a program, as measured by subsystem outage rates.