Excessive noise levels from the concrete section of the M25 between junctions 8 and 9 are detrimentally impacting residents living close by in Walton-on-the-Hill, Headley, Mogador and Lower Kingswood. Whilst a level of noise is expected from a motorway, the noise levels from this specific stretch are particularly excessive due to the aging concrete road surface. Some residents close by are enduring average noise levels of over 65dB, which can cause sleep disruption along with other negative effects on health and well-being.
At 40 years old, the concrete surface of the M25 between J8 and J9 is now at the end of its life with large gaps between the concrete slabs causing the familiar rumbling sound. As well as causing excessive noise, these gaps also make for a terrible driving experience for motorway users. Rather frustratingly, the excessive noise levels also appear to have limited the proposed expansion of the Surrey Hills AONB, leaving Langley Vale and Banstead Heath outside the proposed new boundary.
In May 2023, I wrote to the CEO of National Highways to highlight the issue and to request that they address the excessive noise levels caused by the aging concrete. In their response, they said they considered the concrete section from J8 to J9 to be in reasonable condition and not need replacing, however they did recognise that the joints generate a large amount of noise. Rather than replacing the concrete in its entirety, they have suggested a possible solution - an innovative new surfacing technique called Next Generation Concrete Surfacing (NGCS).
A few months later, I was delighted to see that a 300m section of the clockwise carriageway close to Walton had been selected for a pilot to trial this new NGCS surfacing technique. The first phase of this work, which involved restoring and narrowing the joints, took place in September, and the second phase, which involves making a series of longitudinal grooves (running in the same direction as the traffic), will take place in 2024. The end result of this NGCS surfacing technique should be a smooth and uniform surface profile. If the technique is found to be successful after monitoring, it can then be applied to the whole section of concrete motorway.
I’m really pleased that National Highways has recognised the importance of addressing the excessive noise for residents living in villages close to the M25 and are now moving ahead with this trial. This is a really positive first step. However, if successful, it will realistically take some time for the necessary repairs to be undertaken to address the noise, so it's important we consider other options to mitigate current noise levels. I am pleased to say that myself and my colleague Marisa Heath have brought Surrey County Council and National Highways together to explore whether there is any opportunity to plant more trees along this stretch of motorway to provide an additional natural sound barrier and to also help deliver on Surrey County Council's ambition to plant 1.2 million more trees in Surrey!
