This paper describes the contents, development process and use of the NHTSA Vehicle Safety Attributes Data Book (NVSADB). This resource was created to provide an automated source of vehicle specifications and dimensions. NVSADB is nine linked SAS data bases which contain quantitative information for approximately five thousand domestic and imported automobiles and approximately five hundred medium and heavy duty trucks. Information on automobiles for model years 1965 through 1984 and for trucks from 1975 through 1981 is currently available. The information this resource contains can be used to relate vehicle characteristics to injuries and fatalities, to provide data for vehicle research computer models, and to support the formulation of accident avoidance concepts. NVSADB was developed for the U.S. Department of Transportation's National Highway Traffic Safety Administration by the Transportation Systems Center.