Measure of Uncertainty: Essential Considerations and Useful Tools for Safety Practitioners and Decision-Makers

Safety practitioners are benefiting from an increasing volume of research that quantifies collision prediction so that a single and precise collision frequency can often be calculated. However, decision-makers are often interested in determining two additional qualities of a safety analysis: accuracy, and the worst-case (and/or best-case) scenario. Though the discussion of variability often removes the possibility of a single precise answer, the examination of errors can quantify the confidence associated with an analysis and therefore greatly increase the defensibleness of an analysis and the soundness of any decisions based thereon (particularly in economic applications). Furthermore, where error can be quantified, there is an opportunity for the safety professional to justify departing from the mean predicted values based on their expertise and experience, as well as a deep knowledge of the relevant research and underlying data sets. This paper presents three methods of discussing uncertainty, or variability, in safety analyses. The application of this information in conducting comparison studies of alternative intersection control is highlighted in a case study that demonstrates how the confidence and defensibleness of safety analyses is improved. These methods present a practical continuation to Highway Safety Manual processes and can serve to enhance an agency's safety policies. (A) For the covering abstract of this conference see ITRD record number 201211RT334E.

• Record URL:
  http://www.tac-atc.ca/english/annualconference/tac2012/docs/session15/rudy.pdf
• 
• Corporate Authors:

  Transportation Association of Canada (TAC)

  401-1111 Prince of Wales Drive
  Ottawa, Ontario  Canada 
• Authors:
  • RUBY, C
• Conference:
  • 2012 CONFERENCE AND EXHIBITION OF THE TRANSPORTATION ASSOCIATION OF CANADA - TRANSPORTATION: INNOVATIONS AND OPPORTUNITIES
  • Location: Fredericton New Brunswick, Canada
  • Date: 2012-10-14 to 2012-10-17
• Publication Date: 2012

Language

• English

Media Info

• Pagination: 16 p.
• Monograph Title: 2012 Conference and Exhibition of the Transportation Association of Canada - Transportation: Innovations and Opportunities

Subject/Index Terms

• TRT Terms: Conferences; Crashes; Dispersion (Statistics); Errors; Hazards; Mathematical analysis; Mathematical models; Probability; Safety; Variables
• Geographic Terms: Canada
• ITRD Terms: 1643: Accident; 6471: Analysis (math); 8018: Canada; 1631: Collision; 8525: Conference; 6512: Dispersion (stat); 6440: Error; 6473: Mathematical model; 6534: Probability; 9150: Risk; 1665: Safety; 9086: Variability
• Subject Areas: Safety and Human Factors; I71: Traffic Theory; I80: Accident Studies;

Filing Info

• Accession Number: 01480594
• Record Type: Publication
• Source Agency: Transportation Association of Canada (TAC)
• Files: ITRD, TAC
• Created Date: May 1 2013 1:20PM