Risk-based approach to speed limits – a step towards Safe System.

Safer speeds are recognised as an integral tool in reducing road trauma, also they are a key pillar of the Safe System philosophy. The current national guidance on speed limits recognises this at the conceptual level but the approach for practical implementation has not been developed to date.
This paper aims to stimulate discussion around the emerging concept of setting speed limits on basis of severe crash risk (fatal and serious injury outcomes). It draws on recent Austroads research to propose several alternative approaches based on crash history, assessment of inherent crash risk due to the road environment, or both. The presented approaches also recognise the intended road function within the network as an indicator of the mobility level expected by the public. The paper explores the possible application of established network-level risk assessment tools such as AusRAP in risk-based approach to speed limits.