Our public information exhibition online

Highways England is committed to reducing environmental impact and improving the quality of life for local communities living within close proximity of our major A roads and motorways

Noise is one of the biggest areas of environmental complaint from communities living and working near our network. Our National Noise Programme aims to reduce noise levels for at least 1,150 Noise Important Areas by 2020, helping to deliver a better quality of life to around 250,000 people.

The purpose of this online public information exhibition is to provide an update on our progress with measures to reduce the impact of traffic and road noise levels from the M40 on local communities along the route.

With our online exhibition, you can view the information at a time and place that is convenient to you. There will also be the opportunity to meet the team, ask questions and provide your views at our local event on 30 June.

Further details are provided at the end of this online exhibition.

Location of the proposed noise barriers

Detailed site assessments, surveys and acoustic modelling have been undertaken to identify locations where noise barriers could be installed and provide the greatest benefit for local communities.

As a result, we have identified 8 sites and are now progressing the detailed design of noise barriers at these locations, as shown on the following plans.

Site 1

Wooburn Moor South: Noise Important Area – 13351 (S)

Site 2

Wooburn Moor North: Noise Important Area – 13351 (N)

Site 3

Loudwater: Noise Important Area – 6043 (N)

Site 4

Flackwell Heath: Noise Important Area – 4153 (S)

Site 5

Daws Lea: Noise Important Area – 4158 (N)

Site 6

Booker: Noise Important Area – 4146 (N)

Site 7

Lane End: Noise Important Area – 4165 (S)

Site 8

Stokenchurch: Noise Important Area – 4246 (N)

What will the noise barriers look like?

A range of design options have been assessed, using a refined noise model, to predict the likely acoustic benefits at each site. Using the outcomes of this exercise and detailed topographical data we have established the optimum alignment, length and height of the eight noise barriers.

How tall? Establishing an optimum height for the barriers

A number of the sites have existing noise barriers, with heights ranging between 1.5-2.5 metres. As a result, installing a barrier less than 3 metres in height would be unlikely to provide a noticeable acoustic improvement.

A barrier height of greater than 5 metres could be problematic to install, and would likely result in other significant environmental impacts, including visual intrusion.

The noise model assessment tested the acoustic impact of barrier heights between 3 to 5 metres, resulting in an optimum height of 4 metres.

Establishing an optimum alignment and length of the barriers

This was determined by applying the following general principles:

  • following the alignment of an existing noise barrier, where present
  • ensuring properties located within the ‘noise important area’ were shielded from M40 motorway noise by each noise barrier
  • positioning the barrier at the top of the slope where the motorway is situated in a cutting
  • positioning the barrier adjacent to the hard shoulder where the motorway is situated on an embankment

What will the noise barriers look like?

A number of design options are currently being considered, which include recycled plastic and timber structures. The images below are illustrative of the types of barriers that are likely to be installed at the M40 sites.

Barrier 1

Barrier 3
Barrier 4

What difference in noise levels can be expected when the barriers are in place?

Outcomes from the noise modelling exercise have been used to produce noise maps to show the likely impact on noise levels when the barriers are installed.

Interpreting the noise maps

What is dB(A)?

This is the most commonly used ‘weighted’ expression of the relative loudness of sound (in decibels) as perceived by the human ear.

A change of 3dB(A) is likely to be perceptible under most normal conditions.


Booker: Noise Important Area – 4146 (N)

Daws Lea

Daws Lea: Noise Important Area – 4158 (N)

Flackwell Heath

Flackwell Heath: Noise Important Area – 4153 (S)

Lane End

Lane End: Noise Important Area – 4165 (S)

Wooburn Moor North

Wooburn Moor North: Noise Important Area – 13351 (N)

Wooburn Moor South

Wooburn Moor South: Noise Important Area – 13351 (S)


Loudwater: Noise Important Area – 6043 (N)

Stokenchurch North

Stokenchurch North: Noise Important Area – 4246 (N)

Stokenchurch South

Stokenchurch South

Reducing environmental impact

Preservation and enhancement of the local environment has been a key consideration from the outset. As part of the scheme, we are committed to:

  • improve the experience for walkers and cyclists using neighbouring local Public Right of Way (PROW) network
  • maximise enjoyment for visitors to – and road users passing through – the Chilterns Area of Outstanding Natural Beauty and Aston Rowant National Nature Reserve

We have undertaken preliminary environmental scoping to inform the assessment and identification of suitable sites for the noise barriers.

All construction will be within the existing highway boundary. More detailed site surveys and assessment are ongoing as detailed design progresses, to maximise scheme benefits and mitigate potential negative environmental impacts.


Surveys have been carried out along the length of the proposed noise barrier locations. The Surveys include early identification of the presence of any protected species, to determine the steps required to carefully manage and preserve habitats both during construction and when the noise barriers are in place.

Landscape and views

The M40 passes through important and valued landscapes. The sensitivity of the local environment is a key consideration in all aspects of our design. Alignment of the barriers and choice of materials sympathetic to this sensitive environment seek to minimise potential visual intrusion whilst maximising the acoustic benefit.

We have undertaken to record all trees and flora within the scheme extents. We will seek to minimise the requirement for removal of vegetation to accommodate the barriers wherever possible. Any areas of vegetation lost during construction will be restored with new planting, to reduce the visual impact of the barriers as the planting matures.

What happens next?

What happens next

Have your say

We hope you have found this online Exhibition useful. We value your views on the scheme and any feedback to help us improve how we communicate in the future.

We have planned a local event where you can meet the Project Team and ask questions and provide your views about the scheme.

Friday 30th June 2017, 1pm-8pm at:

Wycombe Leisure Centre, Handy Cross, High Wycombe HP11 1UP

For any more general queries or questions please contact us at M40noise@highwaysengland.co.uk.