Evaluating the Correlation between Vertical Curve Features and Crash Rates on Highways

Vertical curve features on interstate highways affect traffic operations, vehicle performance, and thus could have an impact on the occurrence of traffic crashes. The primary objective of this study is to evaluate the correlation between vertical curve features and crash rates on interstate highways. Continuous elevation data along interstate centerlines were extracted from the Google Earth for two interstates in Washington State, and five-year crash data were collected to estimate a generalized linear crash prediction model. Several variables representing vertical curve features were considered such as average elevation and grade, standard deviation of elevation and grade in surrounding links, and five types of interstate segments. The results showed that vertical curve features had significant impacts on crash rates. Particularly, crash rate increases as the magnitude of a given grade (either upgrade or downgrade) increases. Variation of elevation and grade were found to have positive impacts on crash rates. Crash rates were found to be much higher in uphill, downhill, sag, and crest segments, when compared to the reference flat segments, respectively, on a given interstate.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHB65 Standing Committee on Operational Effects of Geometrics.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Li, Zhibin
  • Pu, Ziyuan
  • Wang, Yinhai
  • Zhu, Wenbo
  • Chen, Zinqiang
  • Wu, Huafeng
• Conference:
  • Transportation Research Board 96th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2017-1-8 to 2017-1-12
• Date: 2017

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 16p
• Monograph Title: TRB 96th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Crash rates; Highway curves; Highway grades; Interstate highways; Mathematical prediction
• Geographic Terms: Washington (State)
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01628213
• Record Type: Publication
• Report/Paper Numbers: 17-06725
• Files: TRIS, TRB, ATRI
• Created Date: Mar 7 2017 10:25AM