Midblock Crash Analysis Using Precisely Geocoded Crashes

Recent research has shown that the new South Carolina Collision and Ticket Tracking System (SCCATTS) has resulted in dramatically improved geocoded crash positioning that can facilitate statewide safety screening, robust analysis procedures, and formulation of targeted countermeasure programs. The literature has indicated that recommended segment lengths for midblock network screening should be at least 0.1 miles. This research focuses on fixed segment lengths of less than 0.1 miles for statewide screening of midblock crash locations to identify site specific locations with high crash incidence. Crash data were aggregated to short segment buffers in a Geographic Information System (GIS). This “peak search methodology” was tested on different lengths to determine a length most suitable for midblock network screening. The ideal segment length for identifying candidate locations was found to be 100 feet. At this resolution, crashes can usually be associated with a single location specific characteristic such as the presence of a hazardous driveway or geometric characteristic. Longer segment lengths were found to dilute the impact of point source crash locations. The research resulted in ranked lists of midblock locations with the greatest potential for safety improvement. The research found that the peak search short-segment methodology would only be viable with precisely geocoded crash data. The short-segment methodology compared favorably to other network screening methods including network constrained kernel density and an excess Safety Performance Function (SPF) predicted crash frequency for intersection to intersection segments. It is anticipated that implementation of recommendations based on the results of this research will have significant safety benefits for the traveling public.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 545p

Subject/Index Terms

Filing Info

  • Accession Number: 01742286
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-SC-20-1
  • Contract Numbers: SPR 734
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jun 4 2020 12:07PM