AN EXAMINATION OF RELATIONSHIPS BETWEEN ROAD ACCIDENTS AND TRAFFIC FLOW

This thesis suggests that the methods currently used for assessing expenditure priorities do not necessarily identify those sites at which the greatest potential for accident reduction exists. An alternative method for the generation of more cost effective programmes of works, the potential accident reduction (par) method, is proposed and justified. This method adopts the rationale of identifying those sites at which accidents are occuring in higher numbers than would otherwise be expected for such sites with equivalent traffic volumes and locations. This method may provide an improvement of cost effectiveness of road safety expenditure of up to 29% over existing methods. The justification of the method involves detailed statistical analysis of over 10,000 accidents occuring in the lothian region for the years 1979-1982, which demonstrate that there are significant relationships between accidents and traffic volumes and location characteristics. On this basis, models for accident occurrence have been determined. The analyses show that the temporal distribution conforms with a Poisson process and that the spatial distribution is negative binomial. It is shown, for both links and junctions, that whilst there are significant differences between the models for different accident types, they do not, in aggregate, produce significantly better models for all accidents than simple accident models. In addition, the importance of regression-to-mean has been established as an effect which should be accounted for as an integral part of the initial site selection process.

• Corporate Authors:

  University of Newcastle upon Tyne

  ,    
• Authors:
  • McGuigan, DRD
• Publication Date: 1987

Language

• English

Media Info

• Pagination: 184 p.

Subject/Index Terms

• TRT Terms: Costs; Crash rates; Crashes; Distributions (Statistics); Forecasting; High risk locations; Highway design; Highways; Land use; Layout; Location; Mathematical models; Prevention; Regression analysis; Safety; Theses; Traffic control; Traffic flow
• Uncontrolled Terms: Vicinity
• Geographic Terms: United Kingdom
• ITRD Terms: 1643: Accident; 1663: Accident black spot; 1612: Accident rate; 224: Cost; 6572: Distribution (stat); 132: Forecast; 2755: Highway; 2855: Highway design; 356: Land use; 2885: Layout; 6473: Mathematical model; 9149: Prevention; 6588: Regression analysis; 1665: Safety; 8597: Thesis; 654: Traffic control; 671: Traffic flow; 8119: United Kingdom; 393: Vicinity
• Subject Areas: Data and Information Technology; Finance; Highways; Operations and Traffic Management; Safety and Human Factors; Security and Emergencies;

Filing Info

• Accession Number: 00481554
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Apr 30 1989 12:00AM