Long lasting replacement for high friction surfacing

The existing high friction surfacing on this busy slip road at J1 of the M876, near Bonnybridge, had deteriorated, raising concerns over driver safety. The alignment of the slip road with a tight bend leading from a 70mph zone down to 30mph zone made this an area of high risk for road users. A spike in accident numbers prompted an urgent evaluation to come up with a long-term surfacing solution that would improve safety. Given the importance of this route to local road users, it was important to minimise disruption while work was completed.

After discussions with Amey, the fourth generation term maintenance contractor for Scottish Trunk Roads Unit South East, Tarmac recommended ULTIGRIP a durable, skid resisting, thin surface course incorporating a bauxite aggregate. ULTIGRIP offers similar SCRIM levels to conventional anti-skid products. It is laid using a conventional paving machine, combining the surface course and skid resisting surface in a single layer. This saves time compared to high friction surfacing which is added in a separate process. ULTIGRIP can be reliably installed all year round, reducing the risk that work would need to be re-scheduled due to poor weather. The integrated single layer also prevents delamination which can be a problem with conventional high friction surfacing. As a result it has been proven to last up to three times longer, reducing whole life costs.

Around 900m² of the existing carriageway was planed out to a depth of 50mm and 133 tonnes of ULTIGRIP 10mm asphalt was installed in the chosen grey colour. As planned work was completed in a single night shift and reopened the following day. This meant minimal traffic management requirement and limited disruption for local road users. Using ULTIGRIP allowed the client to improve road texture, enhancing safety on this high risk section of road. The grey colour looked similar to the existing road surface, which avoided the possibility of encouraging risk taking behaviour amongst drivers, which is sometimes seen as a problem. The client is now monitoring this new section of road with a view to using it elsewhere on the region’s road network.