Estimation of Safety Performance Function with Limited Data on Highways

Representation of the Indian studies in the development of Safety Performance Function (SPF) for National Highways is quite low. A great amount of effort is spent on the data collection procedures to develop SPF for Indian conditions. Limited availability of traffic flow data has continuously affected the accuracies of the developed SPF. Nevertheless, with the advent of various mapping application programming interface (APIs) in India, a significant reduction in data collection efforts can be achieved. The purpose of the present study is to develop a simple SPF using surrogate variables such as average travel speed, access density, number of lanes and landuse. Three years fatal crash data (2014-16) for a stretch of 36 km connecting Udaipur to Tidi on National Highway 8 in Rajasthan is utilized for analysis. Travel speed information is extracted using Google API. An easy to use python programme is developed to extract the real time speed information from Google server in a spread sheet format. The information for the landuse, the number of lanes and access density is further extracted from satellite imagery of Google maps. The result of the best fit model highlights that travel speed derived from these mapping services is able to explain the crash frequency per km at 95% significance level. In addition to this, access density is also an important variable to explain the crash frequency per km at 90% significance level.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ANB25 Standing Committee on Highway Safety Performance.
• Authors:
  • Malik, Leeza
  • Jindal Shukla, Geeta
  • Tiwari, Geetam
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: References; Tables;
• Pagination: 6p

Subject/Index Terms

• TRT Terms: Crash data; Data collection; Highway safety; Traffic data; Traffic flow
• Identifier Terms: Safety Performance Functions
• Geographic Terms: India
• Subject Areas: Data and Information Technology; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01664981
• Record Type: Publication
• Report/Paper Numbers: 18-03318
• Files: TRIS, TRB, ATRI
• Created Date: Mar 30 2018 4:30PM