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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 Transportation 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.

Highway work zones interrupt regular traffic flow and lead to more severe types of crashes, as shown by many studies. In 2009 alone, more than 600 fatalities nationally were work zone related. Analysis of work zone safety can help to identify the risk factors and improve safety; such an analysis requires the consideration of a variety of data sources, including the frequency of crashes in and around a work zone and specific work zone characteristics. The traditional approach, in Wisconsin and many other states, has relied on the presence of a construction zone flag in the crash report and information from targeted work zone studies. The crash report provides a macroscopic view of work zone crashes but does not provide details about the work zones, except when noted in the police officer's narrative description. Targeted work zone studies provide a wealth of information for specific work zones but are limited in number and scope. The Wisconsin Lane Closure System (WisLCS), a centralized scheduling and reporting system for highway lane closures statewide, provides a new opportunity to match crashes to specific work zones on a systemwide level. This paper investigated the ability to match highway crash records from the Wisconsin Department of Transportation to WisLCS lane closure records. A preliminary analysis of work zone safety based on WisLCS closure attributes is presented and verifies the benefits of integrating work zone information. This knowledge can lead to safer work zone operations and planning decisions. The general ideas of this study can also be applied to any similar sets of crash and work zone data.

The Wisconsin Department of Transportation maintains two separate geographic information system databases: one for state roads and one for local roads. Both databases employ linear referencing system (LRS) theory to manage and locate information. Combining data from state and local roads into one system is desirable for the purpose of data management and analysis. This paper's approach combines information from the state route LRS (link ID and offset distance) with information from the local road LRS (node ID) to produce a table that can be employed to transfer data between the systems. A computer program was developed to use this table, along with existing tables in each LRS, to move information from the state route system to the local road system. Quality assurance and quality control techniques are presented along with a long-term implementation approach; both help to update the table bridging these two systems. The approach described does not interfere with the current operation of either system; therefore, no interruption of business practice will occur as this data transfer approach is deployed. Although this approach can transfer any LRS data, a case study of crash data for Dane County, Wisconsin, is used to demonstrate and test the approach. In the case study, crash points on the state routes are combined with local road crashes to produce a complete data set of crashes within the county.