To combat reduction in resources, many agencies have begun to raise the reporting threshold for traffic crashes. Some agencies no longer report property-damage-only (PDO) crashes, unless the vehicle is not driveable or must be towed from the scene. Other agencies have raised the threshold to require reports only on crashes involving injury. Such changes in reporting thresholds will alter the data set available to users of crash data and may create problems for analysis. In order to determine the effect of moving to a towaway threshold, certain questions must be addressed: What are the implications of using a higher crash reporting threshold? What are we losing? If we analyze an issue, would we conclude anything differently? By raising the threshold, could we extrapolate back to the complete crash picture? There are clearly some differences in the reporting practices of the eight Highway Safety Information System (HSIS) States (California, Illinois, Maine, Michigan, Minnesota, North Carolina, Utah, and Washington) that make it inappropriate to combine data for many types of analyses. The purpose of this paper is to quantify the expected effects on data analysis capabilities if one or more of the HSIS States convert to a towaway-and-above threshold. (Author/publisher)
Abstract