#60 Road Safety Audit Harmonisation

Austroads recently released a new Research Report[1] (AP-R747-26) detailing the proposed implementation of national harmonisation of road safety audit (RSA) practices. The report describes a ‘Breakeven analysis’ approach to evaluating RSA benefits, rather than a more traditional cost-benefit analysis. This is due to a reported lack of published research on the ‘relationship between road safety audit quality and outcomes (including crash risk and construction efficiency)’. Austroads engaged key stakeholders, including road safety auditors and relevant road authorities, in consultation, finding room for improvement in RSA practices despite generally ‘acceptable’ quality and standards across the industry.

The Austroads study estimated that nationally harmonised RSA practices would increase present value costs (at 4% discount rate) for road agencies over a 10-year timeframe. Estimated increases for Austroads and road safety auditors were $7.5 million higher than the present arrangement costs. Austroads and relevant authorities would see a saving of $1.543 million over the 10-year timeframe. Road safety auditors would accrue additional costs of approximately $9 million in the same period. Further, according to the report:

For benefits to breakeven with these costs, the proposed nationally harmonised road safety audit practices would need to achieve an increase in the benefits attributable to road safety auditing of 1.0% to 1.5% (depending on the adopted discount rate). At the 4% discount rate used to estimate the costs of the proposed harmonisation, this is equivalent to realising the following crash reductions:

• Fatal crashes – 0.7 crashes over 10 years or 0.07 crashes per year, or

• Hospitalisation crashes – 10.7 crashes over 10 years or 1.07 crashes per year, or

• Medical treatment crashes – 53.6 crashes over 10 years or 5.36 crashes per year.

While the above estimates from national RSA harmonisation represent small crash reductions to cover the associated costs, they nonetheless also represent progress toward Safe System and Vision Zero objectives. Some of the specific benefits expected to result include: harmonisation of road safety auditor registration requirements; a single pool of qualified auditors; knowledge sharing; enhanced reliability and confidence; and allowing auditors to work more easily across jurisdictional boundaries.

Other research

As suggested by Austroads, compared with many other road safety research topics, there is relatively little literature on the effectiveness of RSA as a crash reduction and mitigation tool. It is also noted that as RSA practices evolve over time, including in the development of virtual approaches, older research may become outdated. However, a Canadian study did attempt to specifically quantify the benefits of RSA using a highway upgrade as a case study[2]. Methodology included a comparative analysis of safety performance at 5 similar highway facilities using collision prediction models with RSA as a key variable. For the relevant highway section:

… RSAs contributed to an estimated reduction in the overall collision rate of 0.144 collisions per million-vehicle-kilometres (42%) and a total collision cost savings of nearly CAD$1.8 million per year. Similarly, a comparison of the output of collision prediction models and the observed values from the Fredericton-Moncton Highway indicated that applying RSAs contributed to an estimated total reduction in collision rate of 0.084 collisions per million-vehicle-kilometres (24%) and a total collision cost savings of over CAD$3 million per year. While the improved safety performance of the Fredericton-Moncton Highway may not be solely attributed to the inclusion of the RSA process, the results of this study would suggest it has made a substantial contribution.

[1] Austroads (2026). National Harmonisation of Road Safety Audit Practice: Benefit-Cost Analysis (AP-R747-26). Sydney, Austroads.

[2] Gunter, C.A. (2007). The Effectiveness of Road Safety Audits (Masters thesis). Ottawa, University of New Brunswick.