Roads regulator challenges National Highways to accelerate delivery of noise mitigation by 2025

National Highways has been presented with a challenge by the Office of Rail and Road (ORR) to accelerate the delivery of noise mitigation measures by the end of the current Road investment Strategy 2 (RIS2) period, which runs from 2020 to 2025.

The roads body’s target for RIS2 was to provide mitigation for the noise impact the strategic network causes to 7,500 households. From 2020 to 2023, 4,163 households were mitigated and National Highways expects to mitigate noise affecting a further 829 households by the end of the 2023/24 financial year.

This leaves mitigation to be applied to 2,508 by 2025 to meet the target, which, if achieved, would be the most mitigated by National Highways in a year so far in RIS2.

In response to this, ORR has issued National Highways with a challenge to accelerate the delivery of noise mitigation in order to meet this target.

ORR highways senior performance analyst Haydn Gill said: “Vehicles travelling on the strategic road network, especially at high speed, are noisy.

“At motorway speeds most noise comes from tyres rolling on the surface, with engine noise more audible at slower speeds. The UK Health Security Agency recently completed a study adding to existing evidence that transportation noise exposure contributes to worse health outcomes and lower quality of life.

“ORR holds National Highways to account by reporting on progress against noise mitigation targets, highlighting areas for improvement and through advising the Department for Transport.

“ORR receives regular reporting against key performance indicators, including the number of households mitigated from noise.”

According to ORR’s most recent annual assessment of National Highways, released in July, the roads body had identified 2,218 mitigations that it was confident it could deliver in the final two years of RIS2. This would leave a further 1,119 mitigations required to meet its target of 7,500.

The Department for Environment Food and Rural Affairs has identified locations experiencing the highest noise levels as part its Noise Action Plan: Roads. These areas are designated as Noise Important Areas (NIAs).

National Highways mitigates noise through a variety of means, with attempting to control the noise at its source being the first thing to be considered. This can be achieved by using lower noise surfacing on the roads.

According to ORR, research shows a reduction in noise from passenger vehicles can be between 3-4dB compared to older surfacing materials.

Gill said: “National Highways installs lower noise surfacing as standard on new roads and when resurfacing existing roads. It also considers resurfacing with lower noise surfacing in NIAs before planned renewal periods.”

Other techniques include installing barriers to mitigate noise by up to 10dB on large areas. ORR stated National Highways considers the engineering feasibility and value for money before installing a barrier.

A further method used by National Highways to mitigate noise on households is through its insulation programme, where it offers to upgrade households’ windows and insultation to reduce noise levels inside the house.

Designated funds are used to provide insulation for households that qualify for one of three categories. The categories state households must be within NIAs mitigated using barriers since 2015, but which aren't protected by the barriers, have been identified as eligible for insulation under the RIS1 insulation scheme, but haven't yet been insulated, or are within an NIA prioritised for insulation under the RIS2 insulation scheme.

The designated funds are provided through National Highways’ Environment and Wellbeing designated fund. This is a £410M fund to be spent on improvements to biodiversity, noise, air quality, flooding, water quality and carbon emissions, although a certain amount of that is ringfenced by the government especially for mitigating NIAs. National Highways is expecting to spend £123M from the Environment and Wellbeing designated fund over 2023 and 2024, according to ORR.

Gill said: “Noise mitigation is an important issue and ORR will continue to monitor National Highways’ progress as it approaches the final years of the programme.”

National Highways  principal noise adviser Ian Holmes said: The Noise KPI target is a five year target with no targets for individual years within the roads period. We expect to need to deliver around 2,500 households in the last year of the roads period to meet this five year target.

"Whilst this will be the highest achieved in a single year, we have demonstrated we can achieve this scale of delivery as we delivered 2,111 households in 20/21.

"Design work for schemes due to be delivered during the reminder of the roads period is well progressed, and we are confident that the five year target will be met.   

“The majority of the schemes planned for delivery in 24/25 are schemes to provide lower noise surfacing, and whilst some of these schemes could, in theory, be brought forward into 23/34, we have made the decision to deliver them through the warmer months of the spring and summer of 2024, to reduce the potential for adverse winter weather to cause additional costs or delays."

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