TfB’s summer surface dressing programme completed

Etnyre Chipper Spreader

Transport for Buckinghamshire’s (TfB) surface dressing programme for 2020 was completed on 21st July, with the aftercare due to be completed by the end of August.

The 2020 surface dressing programme was completed with 302,000m2 of treatment laid during the 24-day programme. As well as the 20 sites scheduled on the programme, an additional 17 roads from the 2019 programme were added to complete outstanding remedial work. Consideration was also given to deliver the programme around the access required to the household waste site in Amersham and filming at Pinewood Studios.

Since the completion, TfB’s specialist contractor has been continuing with the required aftercare, including sweeping and sign collection. Road markings and road studs that need to be re-applied are well underway and expected to be completed shortly, weather permitting.

The communications regarding the programme were stepped up this year, with regular updates and images on TfB’s social media channels, which were well received by the public and local councillors.

The process of surface dressing involves hot asphalt being sprayed onto the surface of the road, followed by the application of chippings which are then rolled in. This cost-effective way of maintaining a road, restores the skid resistance and seals the surface, while extending the life of the road by up to ten years. Surface dressing also contributes towards pothole prevention, by creating a waterproof seal that prevents surface water getting into the road structure.

Once surface dressing has been completed, the road is swept at regular intervals to remove the majority of loose chippings from the surface, which can then be driven on almost immediately. An advisory reduced speed limit is put in place to allow traffic to push the remaining chippings into the asphalt, before the site has a final sweep after seven days. After this, the road markings can then be re-painted.

With the advisory speed limit in place, TfB advised drivers to take care and ensure they lower their speed limit. This is not only to help push the chippings into the asphalt, but also for their own safety.

TfB worked with their contractor, Eurovia Specialist Treatments, using an innovative piece of equipment, the Etnyre Chipper Spreader, to carry out surface dressing. The machine has the capability to spread the treatment across a carriageway width of up to 6.1m and was first used in Buckinghamshire last year. The advanced on-board computer manages the rate of spread of the chippings so that material usage can be improved. The speed of the surface dressing process can also be varied, improving efficiency on roads where the machine can be fully extended.

Using the Etnyre Chipper Spreader means that some roads in Buckinghamshire can be treated in one pass, minimising or even eliminating joints, which reduces road closure time and improves the effectiveness of treatment.

Roads included in the surface dressing programme were carefully selected with guidance from the Asset Management team, who have worked in conjunction with councillors and local area technicians (LATs).

LATs have a broad technical knowledge of roads around the county and Councillors have an in-depth knowledge of their local area – combined, they’re able to select the roads that are most in need of repair in order to keep the public safe and the network moving.

Buckinghamshire Council Cabinet Member for Transport, Nick Naylor said: “TfB’s efforts to keep the roads in a usable and safe condition during the ever-changing weather, and change in Government guidelines, has been brilliant. The regular updates on social media were helpful and great to see how much work was being done. Well done TfB.”