Abstract:
One of the key hurdles in identifying unsafe intersections and roadways in Wisconsin is the lack of a complete crash location map, especially for crashes that occurred on local streets. Crash locations are reported in terms of relative offset from an intersection on the basis of on- and at-street name information, which identifies the intersection, and direction and distance information, which identifies the offset. For intersection crashes, the offset distance is typically set to zero. As described in this paper, the Traffic Operations and Safety Laboratory at the University of Wisconsin, Madison, has developed a system to automate the mapping of Wisconsin local road crash locations. The location mapping algorithm involves the integration of two separate Wisconsin Department of Trans¬portation databases: the Wisconsin crash database of police traffic accident reports and the Wisconsin Information System of Local Roads (WISLR). The application of WISLR, which is an inventory of local roads with details such as traffic information, pavement condition, and roadway geometry, provides invaluable access to more comprehensive safety analysis. Although the methodology introduced is specific to these two databases, the general ideas can be applied to any similar sets of crash and geographic information system databases. The final result is a pinpoint map of all the intersection and segment crashes that occurred on local roads in Wisconsin, along with the complete crash information associated with each mapped crash. The algorithm developed with this methodology is able to map approximately 79% of the intended pool of available crashes. Quality evaluations indicate that the mapping is almost 98% accurate.
