A NEW METHOD FOR ACCIDENT ANALYSIS. PROCEEDINGS OF STRATEGIC HIGHWAY RESEARCH PROGRAM AND TRAFFIC SAFETY ON TWO CONTINENTS, GOTHENBURG, SWEDEN, 27-29 SEPTEMBER, 1989

The evaluation of the effectiveness of safety improvements using accident data has been a difficult task complicated by anomalies such as the regression-to-the-mean phenomenon, lack of control through traditional experimental design considerations, and insufficient sample sizes (e.g., accident frequencies and/or number of experimental units-sites). Statistical methods have been proposed to remove subjective biases which may confound conclusions in such cases. This study, funded by the Federal Highway Administration, examines various statistical procedures under a variety of applications to determine which procedures are most effective under what circumstances. Examples range from the simplest before/after design with no comparison group to multiple observations in time on a before/after with comparison group study. These procedures were applied to situations with few sites and high accident frequencies (such as changing posted speed on multilane high volume highway sections) as well as situations with many sites but low accident frequencies ( such as signalization at intersections). Both actual and simulated data is used in these comparisons. The sophistication of the statistical methods range from the most elementary procedures currently in use to more recently proposed sophisticated methods of Empirical Bayes estimation and time series analyses. Recommendations are made regarding which procedures are optimal for specific study designs. Also, design considerations are proposed which may alleviate problems and simplify the statistical analysis apriori to data collection.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03476030
• Corporate Authors:

  Swedish National Road and Traffic Research Institute

  Drottning Kristinas Vaeg 25
  S-11428 Stockholm,   Sweden 
• Authors:
  • Pendleton, O J
  • Morris, C N
• Publication Date: 1990

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 189-210
• Serial:
  • VTI Rapport
  • Publisher: Swedish National Road and Transport Research Institute (VTI)
  • ISSN: 0347-6030

Subject/Index Terms

• TRT Terms: Analysis; Crash records; Data analysis; Evaluation; Mathematical analysis; Measures of effectiveness; Safety; Statistical analysis
• Uncontrolled Terms: Accident avoidance; Effectiveness
• Subject Areas: Data and Information Technology; Highways; Safety and Human Factors; I81: Accident Statistics;

Filing Info

• Accession Number: 00494079
• Record Type: Publication
• Source Agency: Swedish National Road and Traffic Research Institute
• Report/Paper Numbers: 351A, HS-040 861
• Files: TRIS
• Created Date: Apr 30 1990 12:00AM