Road Design
- Publication no: AP-R607-19
- ISBN: 978-1-925854-47-3
- Published: 11 September 2019
- PDF (free) Download
Rollover crashes are an undesirable outcome in a substantial proportion of casualty crashes on high-speed roads. Rollovers are especially over-represented in run-off-road crashes due to their direct interaction with the roadside geometry.
This project sought to identify and quantify road and roadside design factors associated with rollover events in run-off-road crashes on high-speed rural roads and with high-severity outcomes. However, the data analysis provided largely non-statistically significant results, and few conclusive factors can be drawn from this work due to data limitations. Therefore, expected inputs to the update of the Guide to Road Design Part 6 are not available from this work. The update to the Guide to Road Design Part 6 will therefore use an alternative or theoretical method for estimating rollover crash risk as input to run-off-road crash mitigation. The literature review did reconfirm known contributing factors including sharp curvature, lack of sealed shoulders, roadside slopes and ditches, hitting unforgiving roadside objects (high-severity risk) and vehicle factors.
- Summary
- 1. Introduction
- 1.1 Background
- 1.2 Objectives
- 1.3 Scope
- 2. Methodology
- 2.1 Literature Review
- 2.2 AusRAP and Crash Data
- 2.3 Modelling Methods
- 2.4 Suggested Guide Amendments
- 3. Literature Review
- 3.1 Risk Factors for Occurrence and Severity of Vehicle Rollover Crashes
- 3.2 Summary of Rollover Risk Factors
- 3.3 Measures to Reduce the Risk of Vehicle Rollovers
- 4. Modelling
- 4.1 Analysis of Rollover Crashes
- 4.2 Factors Affecting Rollover Crashes
- 4.3 Risk Factors for Run-off-road Casualty Crashes
- 4.4 Risk Factors for Rollover Events and Crash Severity
- 5. Discussion
- 5.1 Interpretation
- 5.2 Data Limitations
- 5.2.1 Batter Slope
- 5.2.2 Barriers
- 5.3 Safe System Relevance
- 5.4 Knowledge Gaps and Research Opportunities
- 5.5 Summary of Findings
- 6. Conclusions and Suggested Amendments
- 6.1 Suggested Guide Amendments
- References
- Appendix A Crash Data Analysis