Accident Prediction Models for Evaluation of Safety Performance on Two-Lane Rural Highways

At a European level, road accident fatalities on “two-lane rural roads” constitute about 60% of the total number of fatalities caused by road accidents. This paper presents a comprehensive procedure to define an Accident Prediction Model (APM) for two lane road sections based on road features related to the safety performance of the stretch. Firstly, significant variables related to the exposure, geometry, consistency and context factors were identified for the segmentation of highways into homogeneous sections. All the basic data were obtained from a low cost surveys purposely set up. In particular, differential cinematic Global Positioning System (GPS) surveys were used to define the horizontal alignment and Road Safety Inspections (RSIs) were carried out in order to quantify the other road characteristics related to safety. The latter part of the paper focuses on the calibration of APMs able to estimate the expected number of accidents on homogeneous sections of different lengths that can be characterized by constant values of the explanatory variables previously defined. Several APMs were calibrated using the Generalized Linear Model approach (GLIM). Finally, considering the statistical significance of the parameters related to exposure, geometry, consistency and context factors, and the model’s goodness of fit measures, 19 models were ranked and three APMs were selected as best models. The first one is a base model, function of length and traffic only, which can be used along with an Empirical Bayesian calculation to conduct network screening analysis. The other two models represent the best statistical fit with significant variables related to exposure, geometry, consistency and context factors.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Cafiso, Salvatore
  • Di Graziano, Alessandro
  • Di Silvestro, Giacomo
  • La Cava, Grazia
• Conference:
  • Transportation Research Board 88th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2009-1-11 to 2009-1-15
• Date: 2009

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 20p
• Monograph Title: TRB 88th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Bayes' theorem; Crash data; Empirical methods; Fatalities; Geometry; Global Positioning System; Rural highways; Safety; Traffic crashes; Traffic models; Two lane highways
• Uncontrolled Terms: Crash prediction models; Safety performance
• Subject Areas: Highways; Safety and Human Factors; I81: Accident Statistics;

Filing Info

• Accession Number: 01124193
• Record Type: Publication
• Report/Paper Numbers: 09-1937
• Files: TRIS, TRB
• Created Date: Mar 16 2009 7:22AM