The effects of converting to a towaway reporting threshold on future data analysis capabilities are quantified. The results from the four states used in the analysis (Illinois, Michigan, Minnesota, and North Carolina) revealed that only 51.7 percent of all crashes would be included using a towaway threshold. Only 33.7 percent would be included using an injury threshold. In general, a towaway threshold would exclude more crashes on urban streets than on rural roads. For most road classes, 40 to 60 percent of crashes would be excluded. With a towaway threshold, about 40 to 60 percent of angle/turning and rear-end crashes, but only 18 to 32 percent of backing/ parking and animal crashes, would be included. Run-off-road crashes would be less affected. For most vehicle types, only 30 to 60 percent of crashes would be included. Using a towaway threshold will seriously affect the comprehensiveness of crash records, and thus, the ability to identify and improve high-hazard locations. Technological, institutional, and organizational strategies for improving reporting thresholds are suggested.