Action Planned
The RSTA reviewed specifications and processes with members and will discuss concerns raised by the Coroner relating to asphalt preservation systems with National Highways, providing an update after the meeting. (AI summary)
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Dear Julie
Thank you for your letter dated 10th July 2025, with the accompanying ‘Regulation 28: Report to Prevent Future Deaths’ in relation to the very sad death of Paul David RANSOM on the 24th May 2023.
The RSTA would like to express our condolences to Paul’s family and friends.
I acknowledge the themes identified by the Coroner as cause for concern, to include:
Early life skid resistance, post treatment / change in the level of friction Study into accidents rates - not specific to motorbikes Guidance on post treatment signage Site categories gradients, bends, limited site lines – particularly for motorcycles
The RSTA and its supplier and contracting specialist member representatives held a meeting to review the Specification, Codes of Practice and processes associated with the application of preservation systems.
Our response to this notice make reference specifically to the asphalt preservation treatment and does not relate to other road surface treatments or resurfacing.
Early life skid resistance
Asphalt preservation systems are preventive surface treatments certified under a Highway Authority Product Approval Scheme, in which an independent, accredited laboratory will have undertaken robust testing, including that of post treatment skid resistance, deeming the systems suitable for use on UK roads.
Mike Hansford - Chief Executive & Director. Registered office: Technology Centre, Glaisher Drive, Wolverhampton Science Park, Wolverhampton, WV10 9RU. RSTA is a trading name of The Road Surface Treatments Association Limited, a Company Limited by guarantee No. 375993 London Following the application of the preservation treatment, a grit is applied as a sacrificial layer which serves to manage initial skid resistance, and to re-abrade the aggregate through the effects of trafficking, to remove any remaining film on the road surface.
Asphalt preservation treatments typically take from 30 minutes to two hours to ‘cure’ depending on conditions, which on the day of the collision, were reported to be good. The treated surface is not reopened to traffic until such time that the application of grit has been completed and the treatment has fully cured. My understating is that the collision occurred approximately six hours, post treatment, having been fully inspected and deemed suitable to be reopened to traffic.
The site was closed following the collision and Police conducted testing of skid resistance during the closure as part of their collision investigation. Therefore without any vehicle actions, the surface properties would be very similar to that at the time of the collision.
The skid testing results confirmed that both skid resistance values and grip levels were satisfactorily above the minimum investigatory values required, which is contrary to the testimonies of some of the witnesses who had described the road as being slippery.
The site was therefore reopened by the Police, without any post-treatment signage, indicating that there were no further safety concerns.
Through the HAPAS testing process, we are confident that quality products and systems are applied to roads, and by trained and competent installers, which ensures post preservation treatment skid resistance values will meet the required investigatory levels.
Accident Rate Studies not being motorcycle-specific
The RSTA is unable to offer any comment on any statistics or studies relating to collisions involving motorcycles, specifically.
The Department for Transport may have a more detailed breakdown of collision data, involving motorcycles.
Post-Treatment Signage Guidance
Currently, there is no requirement for post-treatment signage on sites treated with asphalt preservation.
Asphalt preservation systems undergo rigorous independent testing and accreditation under the Highway Authorities Product Approval Scheme (HAPAS), including:
A Type Approval Installation Trial (TAIT), involving comprehensive independent testing to UK and European standards covering both pre- and post-treatment skid resistance, grip, and surface texture. Manufacturing under ISO 9001 quality standards. Annual installation audits by independent bodies such as the British Board of Agrément (BBA), ensuring treatments are applied according to approved methods.
Mike Hansford - Chief Executive & Director. Registered office: Technology Centre, Glaisher Drive, Wolverhampton Science Park, Wolverhampton, WV10 9RU. RSTA is a trading name of The Road Surface Treatments Association Limited, a Company Limited by guarantee No. 375993 London This independent testing confirms that by the time a treated road is reopened to traffic, skid resistance values will be restored to the specified investigatory levels, therefore the process for these systems, do not require any signage.
Preservation treatments are only recommended for sites where SCRIM data is above investigatory levels.
Sites falling below this threshold are deemed unsuitable for preservation treatment. All RSTA members confirm that pre treatment skid resistance data is routinely requested, which forms an essential part of site suitability considerations.
A site-specific survey and risk assessment is completed for all sites prior to treatment, whereby any additional risk factors and mitigation measures that may be required, including that of any signing, are identified.
Site Categories – Gradients, Bends, and Limited Sight Lines
The site-specific survey and risk assessment which is completed for all sites prior to treatment, would incorporate any risk factors linked to gradients, bends and sight lines, and may also include any collision history on the section of road being treated.
This would be a discussion between the specialist contractor and the client / principal designer or designer and would involve consideration of any requirement for warning signs on completion of works prior to reopening to traffic.
Further evidence for clarification
I understand there was reference in one of the testimonies at the inquest, to slippery road warning signs once being required to be put out on new ‘thin surfacing’ type materials (which is a term used to reference a type of asphalt surface course product). These materials have a thicker binder film. The national guidance on management of these thin surfacing materials removed the requirement for slippery roads signs to go out on these sites.
These thin surfacing materials, unlike asphalt preservation systems, do not have an application of grit applied post treatment to manage skid resistance, so the two treatments / processes cannot be compared.
My understanding is that there was also reference to surface dressing, where signing is placed on the highway, post treatment. This is an entirely different process and this signing manages the potential risk associated with loose chippings and therefore reduces the speed of traffic, until such time the final sweep has been completed and loose chippings have been removed. This process is not required for preservation treatments.
Next steps
The specifications (Specification for Highway Works) and design manual documents (Design Manual for Roads and Bridges) are compiled by National Highways as part of their Manual of Contract Documents for Highway Works (MCHW), and these documents are often used by local highway authorities.
Mike Hansford - Chief Executive & Director. Registered office: Technology Centre, Glaisher Drive, Wolverhampton Science Park, Wolverhampton, WV10 9RU. RSTA is a trading name of The Road Surface Treatments Association Limited, a Company Limited by guarantee No. 375993 London We are due to meet National Highways to discuss the newly revised specification documents, which will be published in late September/early October.
We will specifically discuss the concerns set out by the Coroner in this Notice, relating to asphalt preservation systems.
I will respond to you again, with an update of the outcomes of that meeting. In the meantime, if you have any further questions or require any clarifications, please get in contact with me.