Road safety

Cover of Infrastructure/Speed Limit Relationship in Relation to Road Safety Outcomes
Infrastructure/Speed Limit Relationship in Relation to Road Safety Outcomes
  • Publication no: AP-T141-10
  • ISBN: 978-1-921551-97-0
  • Published: 1 January 2010

The objective of this project was to provide advice to jurisdictions on appropriate speed limit setting policy in light of harm minimisation (the Safe System approach). This advice was based on the improved understanding of the relationships between infrastructure, speed limits, driver selection of speeds and crash outcomes.

The project consisted of a review of Australasian and international literature regarding the harm minimisation approach in road safety and speed limits. Data analysis was carried out to identify the relationships between different elements of road infrastructure and crash outcomes. This body of research was evaluated by an expert group of Austroads stakeholders to identify the road infrastructure features relevant in speed limit setting. The stakeholders provided input into guidance on appropriate speed limit setting policy in the context of harm minimisation.

The project provides a set of revised guiding principles for speed limit setting based on harm minimisation (the Safe System approach), road function, road infrastructure and driver selection of speeds.

  • SUMMARY
  • 1. INTRODUCTION
  • 2. METHOD
    • 2.1. Literature Review
    • 2.2. Data Analysis
    • 2.3. Evaluation of the Infrastructure/Speed Limit Relationship
    • 2.4. Guidance on Speed Limit Setting Policy
  • 3. OVERVIEW OF THE SAFE SYSTEM IN RELATION TO SPEED LIMITS
    • 3.1. Safe System Principles
    • 3.2. Harm Minimisation and Speed Limits
  • 4. SPEED LIMITS, SPEEDS AND CRASH OUTCOMES
    • 4.1. Effect of Speed Limit Change on Mean Speeds
    • 4.2. Mean Speed and Crashes
    • 4.3. Free Vehicle Speeds and Crashes
    • 4.4. Models and Estimates
    • 4.5. Summary
  • 5. INFRASTRUCTURE AND DRIVER SELECTION OF SPEEDS
    • 5.1. Australian and New Zealand Research
    • 5.2. Overseas Research
    • 5.3. Summary
  • 6. ROAD INFRASTRUCTURE, SPEED LIMITS AND CRASH OUTCOMES ( DATA ANALYSIS)
    • 6.1. Road Type and Speed Limit
    • 6.2. Traffic Flow
    • 6.3. Access Control
    • 6.4. Lane and Shoulder Width
    • 6.5. Horizontal Alignment
    • 6.6. Median Width and Setback
    • 6.7. Other Road User Factors
    • 6.8. Summary
  • 7. EVALUATION OF THE INFRASTRUCTURE/SPEED LIMIT RELATIONSHIP
    • 7.1. Harm Minimisation Speed Limits
    • 7.2. Infrastructure, Speeds and Speed Limits
    • 7.3. Stakeholder Input into Guidance on Appropriate Speed Limit Setting Policy
    • 7.4. Summary – Road Infrastructure Features Relevant in Setting Speed Limits
  • 8. GUIDANCE ON SPEED LIMIT SETTING POLICY
    • 8.1. Speed Limit Setting Principles
    • 8.2. Implementation
  • 9. DISCUSSION
  • 10. CONCLUSIONS AND RECOMMENDATIONS
  • REFERENCES
  • APPENDIX A LIST OF WORKSHOP PARTICIPANTS
  • APPENDIX B RECONCILIATION OF DIFFERENT SPEED LIMIT SETTING APPROACHES