The purpose of this research was to determine the number and characteristics of drivers who had a high accident involvement during a particular year. Then, using information available in the accident and driver record files, the changes in their characteristics and accident involvement during the following four year period were determined. Accident record summaries were collected for the years 1967 through 1971 for all drivers who were identified as having been involved in three or more accidents during the year 1967. Driver record summaries were collected for drivers involved in three or more accidents during the year 1967 and a total of five or more accidents during the entire five year study period. Included in the final analysis were 776 drivers for which both driver and accident record summaries had been obtained and an additional 1288 drivers for which only accident records were collected.