Safety Performance Functions for Divided Four-Lane Inter-City Highway Under Heterogeneous Traffic Flow

Inter-city/rural highway contributes to majority of crashes on four-lane divided highways in India, a developing country. According to recent statistics, 54% of the crashes occurred on inter-city highways in the country in the year 2016. Default Safety Performance Functions (SPFs) in the Highway Safety Manual (HSM) are site-specific and need local calibration for application in other countries. In order to adapt the SPF developed by the HSM, calibration factors were estimated for four-lane divided inter-city highway as well as for un-signalised three and four-legged intersections using the Interactive Highway Design Model (IHSDM). Further the study was carried out to develop site-specific SPF based on local site data using count data modeling approach. The study was carried out on a inter-city highway in plain and rolling terrain and operating under heterogeneous traffic flow. The database used for the analysis includes the geometric design, traffic and exposure characteristics, crash characteristics and other features of the roadway. For safety analysis, the highway was segmented based on fixed length and pavement surface characteristics. Validation of the developed models have been performed based on prediction performance and cross validation. Best fit models were identified based on these results and Akaike’s Information Criterion (AIC). Results from calibration studies indicated that the HSM under-predicts crashes both in the case of segment and intersection safety analysis. The developed SPFs are found to be capable of predicting/evaluating the safety level more accurately on multi-lane divided segments compared to that of calibrated HSM models.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ANB25 Standing Committee on Highway Safety Performance. Safety Performance Functions for Divided Four-Lane Intercity Highway Under Heterogeneous Traffic Flow: This is an alternate title.
• Authors:
  • Vayalamkuzhi, Praveen
  • Amirthalingam, Veeraragavan
• 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: 5p

Subject/Index Terms

• TRT Terms: Calibration; Four lane highways; Highway safety; Intercity transportation; Rural highways; Traffic flow; Traffic safety
• Identifier Terms: Highway Safety Manual
• Geographic Terms: India
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01660987
• Record Type: Publication
• Report/Paper Numbers: 18-06548
• Files: TRIS, TRB, ATRI
• Created Date: Feb 22 2018 9:19AM