Organisation
Derby City Council
Amount awarded
£40,000
Completed
2025
Uploaded to Knowledge Centre
7 October 2025
Many highway authorities measure the skid resistance on key routes and carry out targeted improvements to reduce the risk of collisions in wet conditions. Typically, decisions about when and where to invest are guided by the approaches taken for national roads, which have different characteristics. The lack of evidence to support a risk-based approach on local roads poses a challenge for the effective management of these networks.
Phase 1 of this research, funded by the Road Safety Trust in 2020 – 2021, addressed this gap by examining the link between skid resistance and collision risk on local roads. It proposed new skid resistance thresholds and a decision-framework, “the LASR approach”, to support prioritisation of maintenance funding.
In Phase 2, reported here, a practical trial of the LASR approach has been carried out to determine if it is appropriate for implementation. The main objective was to assess whether the benefits of treatments predicted by the Phase 1 work, i.e. a reduction in collisions on wet roads, are achieved in practice.
Thirteen local authorities participated in the study. Each provided data and identified sites that were treated to improve the skid resistance. Comparable sites were left untreated. Most treatments were carried out between January and August 2022 and the collision history was monitored for approximately 5 years before and 2 years after treatment.
Where treatments resulted in a significant improvement in skid resistance, a 38% reduction in wet collisions was achieved on the treatment sites compared with the comparison sites. As a result of this work, some changes to the thresholds for skid resistance are recommended. The LASR approach appears to be effective in targeting lengths that can deliver safety benefits, and it has the advantage over traditional strategies in that it balances the collision history of a site with the loss of skid resistance in assessing the priority for treatment. This allows areas for treatment to be identified on a preventative basis, before injury occurs.
Feedback from the local authority Steering Group was positive, members being broadly confident in the results and the proposed revision to skid resistance thresholds, and feeling it a realistic strategy to adopt.
The next steps will be to work with the Steering Group towards implementation. The study results will be disseminated more widely amongst local authority practitioners and a short ‘case for change’ will be produced to support local authorities in changing their current policies. The description of the LASR method and the LASR analysis template on the project website will be updated and further Steering Group meetings will be held for authorities that wish to collaborate on implementing the LASR approach.
Click the link below to access the full report:
https://www.roadsafetytrust.org.uk/small-grants-awarded/derby-city-council