Conclusion
This report summarises Phase 2 of Project PRIME, the 3-year (2023 to 2025) programme of road trials in Scotland funded by the Road Safety Trust and Transport Scotland. Throughout this work and the wider context of psychological theory, the approach taken has provided a planned and incremental development of understanding and building of evidence to take the work forward. This has been supported through the publication of scientific journal papers that demonstrate the work has been peer-reviewed and accepted to the highest international academic standards.
The concept of PRIME gateway markings provides a simple and very cost-effective solution to help reduce single vehicle crashes on our roads (which are one of the main collision types for motorcycles).
Across Phase 1 and Phase 2 a total of 47,770 motorcycles have been manually counted and coded throughout the West Highlands with 15,599 lead motorcycles analysed in detail to understand the potential influence of PRIMEs on rider behaviour.
As far as the project consortium are aware, this makes the work the largest motorcycle behaviour investigation of its kind. Overall, the scientific evidence demonstrates that in general PRIMEs promote positive behaviour change by reducing speed, improving road position reducing braking (apart from one trial site where braking increased) and increased use of the road markings when they were installed.
These findings underpin Transport Scotland’s ‘Road Safety Framework to 2030′ that has identified motorcyclists as a Priority Focus Area with a target of 30% reduction in motorcyclists killed or seriously injured by 2030 (Transport Scotland, 2021). In addition, PRIMEs have been specifically recognised in the new Road Safety Strategy (Department for Transport, 2026).
The findings from Phase 2 will be considered in any revision of the Installation Toolkit so that practitioners can incorporate knowledge of PRIMEs into their road safety initiatives. Of particular importance are the insights for where PRIMEs may or may not be of benefit to casualty reduction.
There is also evidence that demonstrates that if PRIMEs are installed, they can have a positive effect on rider behaviour which is sustained over time and carried over to subsequent bends.
Apart from the one site where braking increased, PRIMEs did not have a detrimental effect on rider behaviour. While collision data for the entire trial period are still being collated, early signs point to a reduction in motorcycle injury collisions where PRIMEs have been installed.
The findings support the development of bespoke motorcycle road safety measures by Transport Scotland and supported by the Road Safety Trust that provide an important step in reducing motorcyclist road casualties. By demonstrating the positive influence of PRIMEs on rider behaviour and rider safety, this work showcases Project PRIME as a leader in this initiative for the UK and the world. It highlights the important role of employing Human Factors expertise in road safety initiatives beyond the current work and in casualty reduction and road user behaviour more widely.