Computerized crash analysis systems in which crash data, roadway inventory data, and traffic operations data can be merged are used in many states and municipalities to identify problem locations and assess the effectiveness of implemented countermeasures. By integrating this traditional system with a geographic information system (GIS), which offers spatial referencing capabilities and graphical displays, a more effective crash analysis program can be realized. In a recent FHWA-sponsored study, a crash referencing and analysis system within a GIS was developed within the Highway Safety Information System (HSIS) of the state of North Carolina for the area of Wake County. The system provides the functions needed to edit both tabular and spatial crash and roadway data as well as to perform crash analyses related to intersections, roadway segments, and special highway features, such as bridges. The second phase of the project was undertaken to illustrate the advantages of a GIS-based crash analysis system. The problem selected was identifying and analyzing locations of high numbers of truck-crashes, both along designated truck corridors and on other roadways within the county. The goal of the study was to determine if there are benefits to using a GIS-based crash referencing system over the traditional databases that contain crash, roadway feature, and operations data files and can be linked by location. Specific objectives for the truck-corridor analysis project included ( a) identifying locations of high numbers of truck crashes using the GIS-based system, and ( b) exploring the applicability of nontraditional databases to this type of analysis.