This paper provides an overview of the substantial reduction since 1980 in frequency of medium/ heavy truck accidents, injuries, and fatalities. It also reviews concurrent progress achieved by truck manufacturers, the trucking industry in general, and the U.S. Department of Transportation in cooperatively addressing key truck transportation issues.Single vehicle truck crashes continue to be the largest contributor to truck occupant fatalities; fewer than 13% of all fatal truck crash involvements account for two-thirds of the total number of in-cab fatalities. The majority of fatally injured truck occupants involve ejection and/or rollover.Increasing use of seat belts is the single largest contributor to the declining number of truck occupant fatalities. The occupant fatality rate for medium/heavy trucks improved 60% from 1980 to 1991.A decrease in the overall crash involvement rate for medium/heavy trucks is cited as a second reason for declining heavy truck fatal crash involvements and in-cab fatalities. The paper also compares heavy truck crash involvement and occupant fatality rates with other classes of vehicles.Section 1.0 of the paper deals with truck accident data analysis, 2.0 discusses and provides examples of the cooperative working relationship that have evolved between government and the trucking industry, and 3.0 offers a resume of coordinated truck safety research studies that have been implemented to identify and resolve priority issues. Section 4.0 contains a list of conclusions drawn from the information presented in the paper.