This study reviewed the potential impacts of a towaway reporting threshold (where at least one vehicle is disabled to the extent it must be towed from the scene) on the North Carolina Highway Safety Improvement Program (HSIP) listings and on the locations and types of crash patterns identified on collision diagrams by field engineers. Results showed that there would be significant shuffling of HSIP listings that North Carolina uses to identify, investigate, and treat potentially hazardous locations on the highway system. The results of the crash-pattern analysis indicate that a towaway crash report threshold would make it more difficult for a group of engineers to identify crash patterns and therefore less likely to recommend improvements to certain sites with serious problems.