Agglomerations Noise Action Plan for Scotland:

1. Introduction

Noise pollution, meaning unwanted or harmful sound, can impact human health and well-being in a number of ways, including sleep disturbance, annoyance, and increased risk of cardiovascular disease. Noise occurs from a wide variety of activities in our everyday lives: from our homes, businesses and industry, to how we get around. The World Health Organisation estimates that noise pollution from traffic results in one million healthy life years lost in Western Europe every year^[1].

For the first time environmental noise maps covering all road and rail across Scotland have been produced. The noise maps support the development of the environmental noise action plan covering large urbanised areas (agglomerations^[2]).

This Agglomerations Noise Action Plan for Scotland aims to support policy makers and partners in developing policies and measures to protect human health from harmful exposure to environmental noise. The Agglomeration Noise Action Plan partners with the Transport Noise Action Plan, covering road and rail noise, to set actions up to 2028.

The local authorities, and partners, responsible for implementing this action plan will need to consider the wider implications of any potential action to manage environmental noise, delivering best value through balancing wider environmental, social and economic considerations, including cost effectiveness.

1.1 Executive Summary

The key aim of strategic noise maps is to help inform the public and stakeholders about environmental noise. This Agglomerations Noise Action Plan also sets out three key objectives to support engagement and development of environmental noise policies:

• To improve consideration of environmental noise management in strategic planning;
• For agglomerations to manage, on a prioritised basis, exposure to environmental noise; and
• To work with partners to reduce potential exposure to environmental noise and increase awareness of noise control measures and actions.

The results from the environmental noise maps provide estimates of population exposure to environmental noise in Scotland and broken down to agglomeration. In Scotland it is estimated that 1.3 million people are exposed to environmental noise, above 55 dB, from road traffic and just over 100 thousand people from railways. The number of people exposed to noise levels >75 dB is estimated at 9,000 people (road traffic) and 300 people (railways) from the noise modelling. The regulations set the noise threshold at 55 dB and higher for population exposure statistics.

To support the effective prioritisation and management of environmental noise, noise‑mapping results support the identification of two key area types:

• Candidate Noise Management Areas, areas where noise exposure may require targeted intervention; and
• Candidate Quiet Areas, where good environmental noise quality should be protected.

Local authorities within designated agglomerations will assess these candidate areas and determine where specific noise‑management measures are required. In addition to targeted mitigation, local authorities will also integrate noise‑management considerations into existing maintenance and improvement programmes wherever practical. This approach ensures that opportunities to reduce or prevent noise impacts are embedded into routine works as well as priority projects.

The long-term strategy for noise action planning is to widen engagement across Scotland on noise mapping, build knowledge and share learning on the effectiveness of noise policies and mitigation measures.

1.2 Background

The Environmental Noise (Scotland) Regulations 2006 (the “2006 Regulations”) require Scottish Ministers to:

• produce and adopt strategic noise maps for major roads^[3], major railways^[4] and agglomerations (at least every five years); and
• produce and adopt action plans, informed by the strategic noise maps covering roads, rail, and agglomerations, which must be reviewed, and if necessary, revised every 5 years.

The 2006 Regulations impose separate obligations on airport operators in relation to airport noise:

• airport operators for major airports^[5], and airports within agglomerations, are responsible for making strategic noise maps showing airport noise on a 5-yearly cycle; and
• airport operators for major airports, and those with noise above levels prescribed in the regulations are required to draw up and submit an action plan for that airport, with the action plan to be reviewed, and if necessary, revised on a 5-yearly cycle.

Responsibility for preparing airport action plans rests with the relevant airport operators.

This is the fourth round of producing environmental noise maps for Scotland, with associated action plans. This action plan fulfils the relevant requirements in the 2006 Regulations.

This action plan sets out:

• exposure to environmental noise in large urbanised areas (agglomerations), from the results of the environmental noise maps;
• identification of candidate noise management areas to support management of environmental noise, including noise reduction if necessary;
• preservation of environmental noise quality where it is good, though candidate quiet areas.
• information for the public on environmental noise; and
• adoption of the Agglomerations Noise Action Plan for Scotland, based on the environmental noise maps.

With the move to mapping all road and rail across Scotland, we are taking the opportunity to consolidate the agglomerations actions into a single Noise Action Plan, bringing together an overarching picture for local authorities on environmental noise. This action plan will be relevant to the authorities responsible for transportation in the agglomerations, local authorities (in particular those in agglomerations) with environmental, transport and planning responsibilities, and interested members of the public.

Environmental Noise

Environmental noise is defined as “unwanted or harmful outdoor sound created by human activities, including noise emitted by means of transport, road traffic, rail traffic, and from sites of industrial activity.

The 2006 Regulations do not apply to noise from domestic activities, created by neighbours, work places, inside means of transport, resulting from military activities or the production of renewable energy.

This Agglomerations Noise Action Plan for Scotland 2024 to 2028 is one of the set of five Scottish Noise Action Plans covering the areas described in Table 1 below.

One of the aims of the strategic noise maps is to help inform the public and stakeholders about environmental noise, and to support engagement in the development of a range of potential environmental noise policies, for example:

• prioritising noise mitigation measures like noise barriers and resurfacing roads;
• setting local speed limits to support noise reduction;
• being aware of noise implications in planning of new developments; and
• encouraging engagement on noise considerations in the development of local authority transport, planning, air quality plans and strategies.

1.3 Environmental Noise Mapping

The Round 4 strategic noise maps for Scotland (with input data from 2021) are accessible on Scotland's Noise website^[6]. The noise maps have been produced to show a geographical representation of noise levels across the entirety of Scotland for 2021, showing areas where people are exposed to higher levels of environmental noise.

The noise maps were developed using computer modelling to calculate noise exposure levels. Advances in modelling together with improved data (such as traffic flow, road type and road surface) allowed the noise maps to have a higher level of accuracy and coverage than previous rounds. No actual noise measurements were taken in the production of the strategic maps, as the regulations require noise mapping to be carried out through noise modelling. This approach is taken because sound levels can vary significantly, based on factors including weather conditions or the time of day or year, which would introduce a level of uncertainty into the result.

As a result, the noise mapping data - although useful in helping identify priority areas for investigation - does not necessarily represent an exact picture of the current situation on the ground at any given locality on any given day.

The methodology used is set out in Annex II of the EU Environmental Noise Directive (END)^[7] and is commonly known as the Common Noise Assessment Methods in Europe (CNOSSOS-EU). Due to a new methodology for the calculation of Scotland’s noise maps (CNOSSOS-EU) the Candidate Noise Management Areas (CNMAs) and Candidate Quiet Areas (CQAs) are not comparable with those identified in previous noise action plans.

The 2006 Regulations, with reference to END require that the noise model delivers calculations in relation to:

• noise level on a 10m grid
• a height of 4m above local ground level
• a range of sources and noise types (such as railway routes, building facades).

The mapping also includes a buffer extending approximately 2km around the agglomerations, transport sources, and airport contours

For the evaluation of the CQAs, the L_Aeq,16hr^[8] noise metric has been determined as a 10m grid model output for all noise sources within the scope of the strategic noise maps (road traffic, rail traffic, airport and industrial activity sites). A 10m grid of the maximum noise contribution of any of the noise sources (‘max noise grid’) is used to identify areas of low noise, and the median noise level of the area.

The evaluation, informed by the max noise grid, allows Potential Candidate Quiet Areas to be described in the following two categories:

• Absolute Quiet Areas: where environmental noise levels are low (median noise level of a Potential Candidate Quiet Area is less than 50 dB L_Aeq,16hr) and should be preserved; or
• Relatively Quiet Areas: where environmental noise levels are relatively low in comparison to community noise exposures (25% of population within 1000m of a Potential Candidate Quiet Area is expected to be exposed to noise 10 dB above the median noise level of the Potential Candidate Quiet Area).

For Round 4 noise mapping the Scottish Government went beyond the minimum requirements in the Regulations and mapped noise from all road and rail sources across the whole of Scotland. This is a significant change, as can be seen in Table 2 below, with a significantly larger coverage of roads and rail.

Exposure Statistics

Outputs from the environmental noise model present statistics based on population exposure to noise levels using a weighted average over whole day (with calculations for day, evening and night noise levels) and weighted average over the night period (for sleep disturbance).

The population exposure statistics reflect the estimated level of noise at the exterior of a residential property. Note this measure is based on modelling calculations and not on actual noise readings at these buildings. The model outputs provide an estimate for noise levels that may require further investigation of the actual noise level. In addition, the modelling is based on the noise level outside the building, which will be different to the noise heard indoors – which is dependent on factors like the building construction and room layout.

Industrial Noise

The noise model provides Scotland wide coverage of all road and rail sources, and for agglomerations, includes coverage for noise from industrial sources. The addition of industrial noise within agglomerations is a requirement of the 2006 Regulations.

In developing the noise model locations for industrial sites, information was extracted from the Scottish Pollution Release Inventory (SPRI), with default industrial sound source emissions applied, to support generation of the noise model calculations.

Noise from prescribed industrial sources is managed, and monitored, by the Scottish Environment Protection Agency (SEPA) through site specific environmental authorisations and is therefore addressed outwith this action plan. This approach has been agreed with SEPA and local authorities through the Scottish Environmental Noise Coordination Group (SENCG).

Noise from industrial sources is adequately provided for, and controlled by, the Scottish legislative framework. Prescribed industrial and waste management activities are controlled by SEPA as the 'Regulator' responsible for enforcing the Environmental Authorisations (Scotland) Regulations 2018 (EASR). As part of its role as Regulator, SEPA produces guidance for use in enforcing these Regulations, and has issued specific guidance on the control of noise which will be used when considering applications for, and inspections of, regulated installations. The control of noise at other sites is exercised by the relevant local authority under the Statutory Nuisance provisions in Part 3 of the Environmental Protection Act 1990 (EPA), or by the local planning system.

Due to site specific noise controls (environmental authorisations) already in place for industrial activities, and following consultation with SEPA and the local authorities, it was agreed that industrial noise sources and/or areas would not be included in the action planning process other than at the request of SEPA or the local authority.

1.3.1 A summary of the noise mapping results for all of Scotland

For the first time noise maps have been modelled for the whole of Scotland. Specifically, the Round 4 noise maps include all roads and railways in Scotland. Noise emissions and residential population exposure have been calculated based on this model. The noise maps provide estimates of the population exposure to environmental noise (road traffic and railway sources) in Scotland, and in the five agglomerations (Aberdeen, Dundee, Edinburgh, Falkirk, and Glasgow).

The source identified by the strategic noise maps as exposing the greatest number of people to noise is road traffic. For the ‘all roads’ scenario considered in the noise model, 1,275,900 people are exposed to levels of noise at or above 55 dB L_den, and 608,600 people are exposed to noise levels at or above 50 dB L_night. This represents 23% and 11% of the national population, respectively.

The estimated population exposure to environmental noise in Scotland in set out in Tables 3 and 4. In addition, estimated population exposure to environmental noise in the five agglomerations (Aberdeen, Dundee, Edinburgh, Falkirk, and Glasgow) can be found in Annex B.

Reporting and analysis of the numbers of people exposed to environmental noise in this Noise Action Plan, is by bands in 5dB increments starting from 55dB, as required by the Regulations 2006 (strategic noise maps must satisfy the minimum requirements laid down in Annex IV to the Directive, which defines the required noise bands and associated metrics).