Restoring Skid Resistance in Cyngor Gwynedd
When multiple roads in the Dwyfor area of Cyngor Gwynedd were identified to have skid resistance below the required levels, a solution was required to restore texture and ensure the safety of road users.
During a routine road survey, the Cyngor Gwynedd Highway Inspection team discovered that sections of the A498 Nantgwynant, A497 Nefyn and B4411 Criccieth had friction levels below those set out by the Skidding Resistance Standards CS 228. As a result, vehicles were potentially at risk of skidding incidents when using identified sections of the three roads due to the lower levels of grip.
The loss of macro and micro texture was the result of aggregate embedment caused by the volume of traffic over time, combined with the high temperatures experienced during the summer of 2022. This caused the surface to warm significantly on the south facing road of the A498, leading to ‘fatting up.’ To tackle this issue, Cyngor Gwynedd Highways engaged with WJ Group to implement a cost-effective and low carbon solution.
Safety First
After being approached by Cyngor Gwynedd and assessing the areas in question, WJ Group proposed retexturing the surfaces using the Hydro Retexturing method. This is a surface treatment which uses high pressure water jets to blast excess bitumen out of the road surface to restore macro texture to the pavement surface.
Not only does Hydro Retexturing boost longevity and durability of road surfaces, it is also frequently favoured as it can be used to achieve outputs of 7,000 to 8,000 square metres of treated surface in a single shift. The retexturing plant is mounted to the front of the unit, so traffic management requirements can be kept to a minimum.
For People and Planet
As well as looking for a solution that would increase the skid resistance in these areas, Cyngor Gwynedd Highways sought an option that would meet their sustainability objectives. With a self-imposed carbon neutral deadline, the local authority wanted to limit the amount of CO2 emissions released by any treatment.
When compared to resurfacing, retexturing significantly reduces the carbon impact of a project. It is also a cheaper and faster solution for worn surfaces, helping to prolong the lifespan and restore the road surface to the same – or better – skid resistance as when it was first laid.
Euron Gwyn Jones, Senior Engineer at Gyngor Gwynedd Dwyfor Highways commented: “Retexturing has significantly helped to reduce skid risks across all three sites. It is a process that can be used time and time again if the aggregate is sound, it prolongs the need for more invasive surface treatment. It also helps with reducing the carbon emitted, new material being used and disruption to the road user.”
Across the three roads, 21,825sqm of road was retextured over eight days, minimising disruption for road users. If the same sections had been resurfaced, the programme would have taken almost six weeks to complete. Additionally, the process has positive environmental properties, as it extends the lifespan of surface course layers by maximising the life of the premium aggregates contained within it. This delivers significant savings in carbon, cost and virgin material use, which resulted in approximate carbon savings of 176 tonnes or 96% across the road network.
Gerald Byrne, National Specifications Manager at WJ said: “While safety still remains at the top of the priority list, sustainability is increasingly important for customers. Therefore, environmental impact must remain front of mind when working on road improvement projects. Through collaboration with Cyngor Gwynedd Highways, we’re extremely proud to have generated such significant carbon savings, while crucially improving road safety across the network.”
