Developing a Method to Identify Horizontal Curve Segments with High Crash Occurrences Using the HAF Algorithm

Crashes occur every day on Utah’s highways. Curves can be particularly dangerous as they require driver focus due to potentially unseen hazards. Often, crashes occur on curves due to poor curve geometry, a lack of warning signs, or poor surface conditions. This can create conditions in which vehicles are more prone to leave the roadway, and possibly roll over. These types of crashes are responsible for many severe injuries and a few fatalities each year, which could be prevented to a large degree. This highlights a need for identification of curves with high crash occurrences. The Horizontal Alignment Finder (HAF) Algorithm created by a BYU team in 2014 was improved to achieve 87-100 percent accuracy in finding curved segments of UDOT’s highways, depending on highway type. A tool was then developed through Microsoft Excel Visual Basic (VBA) to sort through curve and crash data to determine the number of severe and total crashes that occurred along each curve. The tool displays a list of curves with high crash occurrences. The user can sort curves by several different parameters, including various rates and numbers of crashes. Many curves with high crash rates have already been identified, some of which will be shown in this report. This tool will help UDOT determine which highway curves warrant improvement projects.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Draft Final Report
  • Features: Figures; References; Tables;
  • Pagination: 119p

Subject/Index Terms

Filing Info

  • Accession Number: 01669057
  • Record Type: Publication
  • Report/Paper Numbers: UT-18.02
  • Contract Numbers: 17-8512
  • Created Date: Apr 25 2018 9:50AM