Learning from 25 years of preventative interventions in Scotland
Within Scotland, there has been a long standing interest in preventative approaches. This report includes 15 case studies of successful preventative interventions introduced in Scotland since devolution and draws together overarching observations.
11. Safeguarding Vulnerable Road Users (Project PRIME)
Project PRIME: Reducing deaths and serious accidents amongst motorcyclists on Scotland’s roads
This case study demonstrates how road markings can enhance rider behaviour when approaching bends. This evidence based road safety intervention was developed in collaboration with riders alongside academic, engineering, and government partners. The evaluation found that the intervention led to significant reductions in speed, improvements in road position and reductions in braking behaviour resulting in reductions in motorcycle injury collisions at the sites where these have been installed.
Introduction
Motorcyclists are one of the most vulnerable road user groups on public roads. [253] New Perceptual Rider Information for Maximising Expertise and Enjoyment (PRIME) road markings which were trialled in the West Highlands of Scotland are an example of a primary preventative intervention designed to improve rider behaviour when approaching bends and prevent them being killed or seriously injured (KSI).
Context
Motorcyclists are around 51 times more likely to be killed on the road than car drivers in the UK.1 [254] In 2019, motorcyclists accounted for less than 1% of all journeys and less than 1% of traffic in Scotland, but represented 7% of casualties. [255]
Scottish data from 2019 showed that between 2018 and the 2004-08 average there had been a smaller reduction in fatal or serious motorcyclist casualties, compared to reductions in car and pedestrian fatalities and injuries.[256]
Between 2015-2019, on average the motorcyclist casualty rate was highest for the 23-25 age group (per thousand population), followed by the 16-22 year old age group.3
Most incidents tended to occur on rural roads at weekends, which are popular times for recreational motorcyclists to be riding.2 UK statistics from 2020 showed that 65% of fatalities occurred in rural areas, and on roads that motorcyclists are unfamiliar with.1
In 2019, 76% of motorcyclists killed were in collisions that took place on roads with a speed limit of over 40mph. [257] ‘Loss of control’ was the most commonly reported contributory factor for motorcycle accidents - 22% of incidents.4 Many motorcycle accidents are classed as rider error, and motorcycle collisions are often a result of loss of control on a bend. This can be due to inappropriate speed or braking prior to the bend, or inappropriate steering or position through the bend itself.1
Evidence suggests that for a number of reasons, left-hand bends are particularly dangerous when riding on the left-hand side of the road, and collisions are more likely to happen on sharp bends than on gentle bends.1
Motorcyclists are known to be resistant to engagement and education about road safety initiatives.1 This is particularly the case for more experienced riders who haven’t undertaken further training, and may have fallen into bad riding habits, and can lack the advanced skills to keep them safe.1 Professor Alex Stedmon who led the research on PRIMEs said:
“It is important to find new ways to engage with motorcyclists and demonstrate that initiatives are based on scientific evidence with a clear rationale for rider safety”.1
Casualties on Scotland’s roads come at a high human and monetary cost. In 2019 the cost of collisions in Scotland was estimated to be over £1.1billion, indicating the clear economic and health benefits to preventative interventions which reduce the risk of casualties on Scotland’s roads.3
Response
Transport Scotland’s Road Safety Framework to 2030 (published in 2021) identified motorcyclists as a Priority Focus Area with a target of a 30% reduction in motorcyclists KSI by 2030.3 One of the responses developed in response to this challenge was a collaborative intervention which brought together behavioural science/human factors[258] research, engineering design and government policy. PRIMEs address the dangers experienced by motorcyclists on road bends, particularly left-hand bends by using dedicated road markings to support better riding behaviour.
The design process involved input from motorcyclists themselves ensuring a “user-centred” approach. A number of potential designs were considered in the context of rider input, engineering and relevant guidance and standards. An underpinning principle of PRIMEs is that they are designed from the motorcyclists’ perspective2 so that riders accept and use the approach.8
This trial built on a previous small scale trial of Perceptual Counter-Measures (PCMs) in New Zealand to support motorcycle safety on bends, which involved the lead author of the evaluation.[259] [260] PCMs have been shown to influence motorcyclists rider behaviour in relation to speed, position, and braking to reinforce better rider behaviour.2
‘The road markings provide a tool for riders to adapt their behaviour on approach to a potential hazard therefore optimising their expertise and enjoyment while remaining safe on the road.’2
Intervention
The intervention was targeted at motorcyclists on Scotland’s Trunk Road Network. PRIMEs ‘help motorcyclists safely navigate approaching demanding bends where it is important that:
(i) speed is suitable for the conditions
(ii) lane position is optimised for negotiating the bend
(iii) motorcyclists do not have to initiate braking whilst negotiating the bend.2
The PRIME road markings are designed as a set of three ‘gateways’ along with road sign information (Figure 2). PRIMEs are designed to be an intuitive behaviour change intervention which primes motorcyclists to ride ‘through the gap’ in the gateway. By doing so this puts riders in the correct position for the bend and allows them to adjust their speed and braking prior to the bend.
Monitoring and Evaluation
PRIME trial sites were identified through analysis of recorded injury motorcycle collisions at bends in the trial area. Project PRIME was the first road trial of its kind and has become the largest known study of motorcyclist behaviour in the world. In total it involved 32,213 motorcyclists, with 9,919 lead motorcycles analysed in detail to understand the potential influence of PRIMEs on rider behaviour.2 Figure 3 below shows the scope of the intervention and evaluation.
The three-year investigation of PRIMEs was conducted over weekends during the motorcycle seasons (May to September) during 2020, 2021 and 2022. PRIME road markings were installed on the approach to bends at 22 trial sites and two comparison sites on roads covering 750 square miles across the West of Scotland. Trial sites were selected based on formal reviews and analyses of collision data, and all sites were of similar standards in relation to road surface and environment. While some right-hand bends were included in the 2020 trial, the main focus of these trials was left-hand bends. PRIME road marking and road sign designs underwent a range of design specification and user feedback prior to use at the trial sites.
The PRIME intervention required close partnership working between a range of professionals across research, management and engineering spheres, including the Road Safety Trust (RST), Transport Scotland (TS), BEAR Scotland and the academic consultancy leading the research, Open Road Simulation. The intervention was part funded by the RST, who provided research funding to TS as the project managers to test the experimental approach. To date Project PRIME has been the largest funded road safety initiative that the RST have supported. BEAR Scotland provided their expertise by offering engineering solutions to make ready the trial sites and the installation of the PRIME markings and signage across Scotland. [261] In addition an internal steering committee including a range of road safety partners was established to widen the stakeholder engagement throughout the project.
This image shows key figures on the PRIME intervention and evaluation. It showed that there were: 22 trial sites and 2 comparison sites which included 32,213 motorcycles (9,919 lead motorcycles). This included 12,949 motorcycles in 2020, 9,594 motorcycles in 2021 and 9,670 motorcycles in 2022.
The intervention included; 1,792 hours of video data; 239 working days of video data; 1,500 miles each weekend; 50,000 total research miles; 297,570 video frames counted to calculate motorcycle speed; 750 square miles of territory.
The evaluation used a quasi-experiment method, combining field observation with formal experimental design.2 Alongside the trial sites, there were two comparison sites where data were collected but PRIME road markings were not installed.
Using a pre- and post-intervention, baseline data were compared with data collected once the PRIME road markings had been installed. Video data were obtained at each site using small and inconspicuous roadside cameras to capture motorcycle speed, lateral position, braking behaviour and use of the PRIME road markings, before and after the installation of PRIME road markings. The evaluation also included 100 interviews with motorcyclists to ascertain rider’s experiences of the PRIMEs and their perceptions of how the PRIMEs might have influenced their behaviour.
Key Findings
a) Positive behavioural changes amongst motorcyclists
The PRIME road markings produced statistically significant positive behavioural changes in motorcyclists’ speed, lateral lane position and braking at sites around the Scottish Highlands. There were no statistically significant differences in motorcycle rider behaviour observed at the comparison sites.2 There was also no evidence of unintended consequences or that PRIMEs had a detrimental effect on rider behaviour, such as a significant increases in speed, dangerous positioning, or increases in braking. Interviews with motorcyclists found that the majority of riders were supportive of PRIME road markings, especially for inexperienced motorcyclists or tourists. There was evidence that most of those interviewed were unconsciously influenced by PRIMEs in the behaviours observed across the trial sites.2
b) Long-term effects of PRIMEs – most behaviour changes last over time
The evaluation also considered rider behaviour changes over one-year and two-year intervals. At the one-year review site the same results were observed in 2021 and 2022 indicating that the behavioural effects of PRIMEs remained constant. At the two-year review site the same results were observed in 2020 and 2022 for all statistically significant behaviours measured except for previous trends in braking that were present in 2020 but not 2022.2
c) Potential to reduce motorcycle casualties
At the time the evaluation report was published (2022) there had been no motorcycle injury collisions recorded at any of the actual sites where PRIME markings were deployed in Phase 1 of the trials. Ongoing analysis of all PRIME trial sites will continue to be conducted.
Learning and Next Steps
The National Transport Strategy (NTS) states “This work not only added to the evidence base of the academic theory underpinning the road markings – but offers a blueprint, which has been tested and proven in Scotland, that has potentially global implications.” 8
The research in Project PRIME has been published in world-leading peer-reviewed journals. It should also be possible to replicate the work through additional research activities that follow the same approach. The project group have also developed an Installation Toolkit to allow other road authorities to replicate PRIMEs in their areas. The toolkit has been made publicly available.
Following on from the positive results observed in the PRIME trials, Phase 2 of Project PRIME is being conducted between 2023 and 2025 (funded by RST with all other costs met by TS), to investigate additional aspects of behaviour change and further broaden the evidence base. The findings will be published in due course but results observed in 2023 (focussing on untreated roads) and 2024 (focussing on right-hand bends) indicate a similar positive behaviour change to that observed in Phase 1. In 2023 Project PRIME received a number of awards including the prestigious Prince Michael International Road Safety Award.
The long term goal of the Road Safety Framework to 2030 is for no-one to die or be seriously injured on Scotland’s roads by 2050.3 Central to this is the ‘Safe System’ approach to road safety delivery, set out in the first NTS Delivery Plan.[262] PRIMEs have identified important behavioural factors that support both the Framework and the ‘Safe System’ approach to motorcycle casualty reduction, particularly in relation to safe road use, safe speeds and safe roads and roadsides.3 2
In contrast to the significant costs of collisions in Scotland, outlined in the introduction, PRIME gateway markings provide an innovative yet low cost and scalable preventative intervention. PRIMEs have the potential to improve road safety for riders and prevent significant public sector spending associated with single vehicle crashes on Scotland’s roads - one of the main collision types for motorcycles.
This evaluation also shows promise for Human Factors approaches to road safety initiatives beyond the current work and in casualty reduction and road user behaviour more widely.9 PRIMEs have implications for road safety, casualty reduction and education initiatives around Scotland, the UK and at international levels.
Contact
Email: Tom.Lamplugh@gov.scot