Asset management

Cover of Development of Safety Related Investigatory Level Guidelines: A Worked Example of Methodology
Development of Safety Related Investigatory Level Guidelines: A Worked Example of Methodology
  • Publication no: AP-T233-13
  • ISBN: 978-1-921991-95-0
  • Published: 10 May 2013

This report provides a worked example for developing skid resistance investigatory level guidelines.

The worked example is sourced from Main Roads Western Australia (MRWA) and relates to texture measurement as a surrogate for skid resistance. A limited number of roads were randomly selected from the MRWA network survey database and used for the development of the guidelines. Correlations between crash rate and texture depth at different site categories and different surface conditions (wet or dry) were examined and analysed. With generally satisfactory correlations between the two key parameters displayed, an example of MRWA texture depth investigatory level guidelines was devised. The report provided a worked example to describe the steps taken in working through the method.

This report is one of the outputs of the Austroads project AT1488 Improving Skid Resistance Measurement. It should be read in conjunction with Austroads report AP-R374-11 Guidance for the Development of Policy to Manage Skid Resistance.

  • 1. Introduction
    • 1.1. Background
    • 1.2. Objectives
  • 2. Review of Data processing method
    • 2.1. Development of Site Categories
    • 2.2. Review of MRWA Network Database
      • 2.2.1. Crash Records
      • 2.2.2. Texture Depth Data
      • 2.2.3. Traffic Volume
    • 2.3. Crash Rate Calculation
    • 2.4. Construction of Data Tables
  • 3. Correlation of Crash rate and Texture Depth
    • 3.1. Crash Rate vs Texture Depth
      • 3.1.1. Site Category 2 (Mid-block), Wet/Dry Crashes
      • 3.1.2. Site Category 2 (Mid-block), Wet Crashes Only
      • 3.1.3. Site Category 1 (Intersection and Curve), Wet/Dry Crashes
      • 3.1.4. Site Category 1 (Intersection and Curve), Wet Crashes Only
    • 3.2. Crash Rate vs Texture Depth: Summary
  • 4. Setting investigatory levels
  • 5. Summary and conclusions
  • References