Optimisation of Road Safety Infrastructure Investment – A Network Safety Plan Tracks

Abstract

Bundaberg Regional Council (Council), in partnership with NTRO, have developed a Network Safety Plan (NSP) to prioritise road safety infrastructure investment and demonstrate achievement of the safest possible road network within the funding constraints of Council.

Australia’s National Road Safety Strategy 2021-30 has introduced the concept of a NSP, however there is currently no framework or practical guidance to assist practitioners in developing them. This paper seeks to share the experience of Council and NTRO in developing the NSP and serve as a potential model for other Council’s to apply.

Like many Local Governments, Council has historically undertaken road safety upgrades in response to observed crashes on the road network, reflecting a site-based, reactive approach to road safety investment that is disconnected from defined network service levels/targets. By developing a network-wide understanding of road safety risk, Council has endeavoured to implement a more proactive approach which prioritises areas of highest risk and seeks to maximise the community benefit from investment in road safety.

The NSP seeks to: 1. Prioritise road safety treatments that have the greatest impact. 2. Optimise investment in road safety by demonstrating achievement of the safest road network within Council’s funding constraints over a defined investment period. 3. Be adaptable to future changes in Council’s funding constraints.

In the absence of a national framework or other relevant guidance, Council and NTRO drew from national best practice for the planned, prioritised delivery of safer road infrastructure to develop a systematic process for NSPs which would produce the intended outcomes.

A network-wide AusRAP (Australian Road Assessment Program) and ANRAM (Australian National Risk Assessment Model) assessment was the first step in the NSP process and provided an understanding of the current safety state and underlying risk factors. Council then adopted an initial safety target (corridor safety vision) of 3-stars or better (AusRAP Star Rating) to align with the National Road Safety Action Plan 2023-25. In conjunction with a separate road hierarchy review and movement and place assessment, this target guided the revision of Council’s road type cross sections, ensuring that new and donated infrastructure aligns with the adopted network safety target. The revised cross sections, applied across the existing road network, then assisted in the identification of safety gaps.

Focussed on treatment of the identified safety gaps, five investment scenarios were evaluated based on different funding levels and/or policy objectives. Evaluation of the road safety impacts for each investment scenario was undertaken using metrics such as BCR, savings in projected FSIs, AusRAP Star Rating and ANRAM risk score changes.

Following several iterations of treatment and investment scenario evaluations, a prioritised infrastructure safety program was able to be developed.

Whilst there will be alternate pathways to deliver the NSP outcome, the approach applied illustrates the key inputs/steps required and provides a case study for how NSPs can be developed and deployed by local governments across Australia.