The reduction of severity of injuries received by occupant of motor vehicles involved in accidents has always been looked upon as a measure of effectiveness of highway safety countermeasures. The largest source of this data has been the investigating police officer's accident report, which indicates the police officer's injury assessment for each occupant of the vehicle(s) involved in an accident. This paper will examine the police injury codes for several hundred occupants of motor vehicle crashes in Washtenaw County, Michigan, through the five year period 1971-75, and compare these codes with the results of clinical examination and follow-up personal interviews of each occupant.