Development of crash modification factors for intersections in Toowoomba city

ABSTRACT

This research outlines the analytical approaches that may be employed to recommend multiple treatments for application to improve safety level at hazardous intersections in regional areas. Data from 106 intersections in the regional city of Toowoomba, Queensland, Australia were used in modelling and subsequent analysis. Specifically, crash prediction models were developed to estimate crash modification factors that could be used to propose remedial measures. A total of sixteen geometric and operational conditions were used as explanatory variables including the number of legs at an intersection, the availability of entering and exiting via through lanes, the presence of left-turning lanes, right-turning lanes, slip lanes, median islands, traffic control, and speed limits on the feed roads. The Empirical Bayes approach was employed to identify five hazardous intersections in Toowoomba for further investigation. The four most suitable techniques for estimating combined crash modification factors were reviewed and then used to propose effective road safety measures for the five selected hazardous intersections. Finally, this research suggests four future areas worthy of further investigation.

Highlights

• Estimated the number of road crashes at intersections using crash prediction models.

• Applied the Empirical Bayes method to identify the most hazardous intersections.

• Combined crash modifications factors were calculated using various techniques.

• Identified the effective countermeasures to reduce the road crashes at hazardous intersections.

KEYWORDS:

• Crash prediction models
• road safety measures
• Empirical-Bayes method
• crash modification factors
• hazardous intersections

Acknowledgments

The first author gratefully acknowledges the financial support from a Tafila Technical University scholarship for carrying out his PhD study at the University of Southern Queensland. The authors acknowledge the data support by the Department of Transport and Main Roads and Toowoomba Regional Council.

Disclosure statement

No potential conflict of interest was reported by the author(s).