An effective procedure was determined for identifying hazardous rural highway locations based on accident statistics. Multiple indicators of accident experience that are necessary include the number of fatal accidents, the total number of accidents, the number of effective-property-damage-only accidents, and the accident rate. Critical levels of these four indicators should vary from state to state depending on the nature of the local safety improvement program as well as local traffic and roadway conditions and prevailing attitudes toward highway safety. Specific recommendations are given for use in Kentucky. Critical accident rates are established using quality control procedures.

To identify hazardous highway locations, it is necessary to distinguish between short highway segments (spots) and large segments (sections) and to further classify spots as intersection and non-intersection locations. Intersection spots should include a distance of 0.15 mile (0.24 km) along all approaches; non-intersection spots should be 0.3-mile (0.48-km), floating segments; and sections should be 3-mile (4.8-km), floating segments. Both spots and sections should be classified by highway type and location. The use of dual time intervals of 1 and 2 years for accumulating and evaluating accident statistics was found to be desirable.

Report Date


Report Number

No. 410

Digital Object Identifier



Accepted for publication by the Transportation Research Board.