Application of Poisson and Negative Binomial Regression for Modeling Road Accidents Under Mixed Traffic Conditions

Studies concern to road traffic safety has been extensively carried out in developed countries over the past few decades. Most of the studies focused on geometric, traffic, and environmental factors. The traffic flow variable, one of the most significant parameter in estimating the accident occurrence, was normally treated as homogeneous flow i.e. only cars, in most of the earlier studies. The problem of mixed traffic flow with varying composition prevails in most of the developing countries. The present study aims to estimate the relationship between accident frequencies with proportion of different types of vehicle in traffic stream. Analysis focuses mainly on rural highways sections, traffic composition, and highway geometric characteristics as independent variables while accident frequency as dependent variable. Accident data for a period of three years from National and State highways of Tamilnadu state, India were used to estimate the model using Generalized Poisson and Negative Binomial regression technique. Models were developed for different accidents types such as fatal, major and minor injuries accidents and best fitting models are presented. The model demonstrates minor accidents are significantly affected by the vehicle types and traffic composition. Fatal and major accidents are found to have positive association with commercial vehicles, while non-motorized vehicles and cars showed negative relationship respectively. The model also points out the significance of the geometric variables such as lane, shoulder and access driveways with accidents. The results showed that presence of commercial vehicles, wider lane, narrow shoulder and increased number of access driveways increase the likelihood for accident involvement.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Chennaiah, Srinivas
  • Dinu, R R
  • Veeraragavan, Amrithalingam
• Conference:
  • Transportation Research Board 86th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2007-1-21 to 2007-1-25
• Date: 2007

Language

• English

Media Info

• Media Type: CD-ROM
• Features: References; Tables;
• Pagination: 14p
• Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

• TRT Terms: Crash causes; Crash rates; Developing countries; Fatalities; Highway design; Injuries; Regression analysis; Rural highways; Traffic lanes; Vehicle mix
• Geographic Terms: India
• Subject Areas: Data and Information Technology; Highways; Safety and Human Factors; I81: Accident Statistics;

Filing Info

• Accession Number: 01044958
• Record Type: Publication
• Report/Paper Numbers: 07-1617
• Files: BTRIS, TRIS, TRB
• Created Date: Mar 30 2007 6:59AM