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Consultation on proposals for transposition and implementation of Directive 2002/49/EC of the European Parliament and of the Council of 25 June 2002 relating to the assessment and management of environmental noise

3. Process for making maps

Overview of environmental noise maps

3.1. As explained in Chapter 2, the END (at Article 7) requires Member States to produce strategic noise maps for agglomerations, major roads, major railways and major airports. Strategic noise maps are a product of a process which aims to secure information about the external noise environment. A noise map is a way of representing levels of noise in a location in terms of a noise indicator.

3.2. Annex II of the END allows for the use of two options to determine the values of the noise indicators L_den and L_night that are required to be used in order to develop the strategic noise maps:

i) the use of noise measurements at many locations to build up a picture of the noise environment; or
ii) the use of computer based noise modelling to generate the required information.

3.3. Capturing sufficient information at the necessary resolution through measurement alone would involve an extremely large survey that would be prohibitively resource intensive. Many measurements would have to be carried out over long periods and the subsequent analysis and collation work would be extensive and expensive. Furthermore, the END requires the information to be gathered separately for the four sources: road, rail, air traffic and industry. Unattended measurements, however, are generally indiscriminate and will record the total noise present at a location, including extraneous noise and it can be very difficult to differentiate between sources. Thus, although noise measurements are likely to have a role to play in the noise mapping process, for example for verification purposes, it will not be possible to provide the level of detail required by the END through measurement alone.

3.4. The Scottish Executive therefore proposes to follow option ii) – for noise maps to be produced using computer based noise models. This process requires the acquisition of information about the noise source of interest; its noise generating characteristics; its location; and how the noise from that source impacts on its surroundings.

3.5. Modelling noise requires information on the noise sources, the transmission path and the receptor as shown in the following table.

3.6. It is clear that a large quantity of potentially complex data is required to enable the noise maps to be generated. Once these input data have been gathered, computer software models are used to determine the noise level at the various receiver locations from the particular noise sources (e.g. road traffic), taking account of the various features described above.

3.7. Several such models exist and the results obtained from these have been used for many years, in particular, as part of noise impact assessments for proposed noise-generating or noise sensitive developments. Different noise calculation models have been developed to model noise from different sources and therefore require particular types of data to run them. The different models required to calculate noise from road, rail, aircraft, industry and ports are discussed in Chapters 5 (Roads), 6 (Rail), 7 (Aircraft) and 8 (Agglomerations, including industry and ports).

3.8. Thus the noise prediction and the noise-mapping processes themselves are well established. What is essentially new with the strategic noise mapping required by the END is the scale and extent of the work and the noise indicators required (for a full description see Annex G). The generic strategic noise modelling process is set out below:

• Determine the scope of what is to be modelled (defined by the requirements of the END and the technical guidance to be published);
• Acquire or generate¹¹ the relevant information for use in the model (defined by the technical guidance);
• Integrate the information into appropriate data management and noise modelling software;
• Carry out the calculations in order to generate noise level results as values expressed in L_den and L_night;
• Combine the results with information on population and their location;
• Determine the population exposure; and
• Produce tables of results and/or graphical representations of the noise results (i.e. noise maps).

3.9. It should be noted that the above is a generic approach and it is the Scottish Executive’s intention to draw up and issue technical guidance on how to make the maps in due course.

Coverage of noise maps

3.10. The END requires (Article 7 paragraph 1) that, by 30 June 2007, the first round of strategic noise maps must be made for:

• the major roads which have more than 6 million vehicle passages a year, major railways which have more than 60,000 train passages per year and all major airports (those which have more than 50,000 aircraft movements a year);
• agglomerations with more than 250,000 inhabitants (sources to be covered within agglomerations are noise roads, railways, aircraft and industrial sites including ports. For more details see Chapter 8).

3.11. As described in paragraph 2.6 of this document Article 7, paragraph 2 of the END requires that noise maps prepared for 2012 (and subsequent rounds) must made for :

• all major roads, major railways and major airports; and
• all agglomerations.

Competent authority to make maps

3.12. The END requires (Article 4 paragraph 1) that competent authorities be designated to carry out the mapping process. As discussed, in the introduction (Chapter 2) and in the different noise source chapters of this document (Chapters 5, 6, 7 and 8), the Scottish Executive proposes that, for most noise sources, the Scottish Ministers be designated as the competent authority for completion of the mapping process.

3.13. The Scottish Executive proposes a different approach to the noise mapping at airports. As discussed in subsequent chapters on each of the noise sources to be covered under the END (Chapters 5, 6, 7 and 8), there are a number of options to determine which organisations and/or authorities carry out the mapping for major roads, railways, airports and agglomerations. The Scottish Executive’s preferred option is for the legal responsibility for the mapping for major roads, railways and agglomerations to lie with Scottish Executive in liaison with other major stakeholders such as Network Rail as necessary. Although retaining legal responsibility for the mapping and therefore the final say, it is likely that the Scottish Executive would engage consultants or other parties to prepare the maps on Scottish Minister’s behalf. The funding burden for this work would be met by the Scottish Executive.

3.14. For airports, the Scottish Executive proposes that each relevant airport operator (whether of a ‘major airport’ or another airport in or near agglomerations covered by the terms of the END) should be the competent authority for making noise maps..

Q3.1: Are you content with this general approach to the mapping for roads, rail, air and agglomerations?

Noise indicators required by the END

3.15. As explained previously, the END requires that the noise indicators L_den and L_night be used to prepare the strategic noise maps (Article 5, paragraph 1). These indicators are explained and discussed further in Annex G. L_den requires the definition of a day, evening and night period; in the UK these will be 0700-1900 hours, 1900-2300 hours and 2300-0700 hours respectively. These periods are recommended in order to remain in accordance with past and current practice where applicable – for example the night period for all modes under the current Planning Advice Note: PAN 56 Planning and Noise)¹² and for the restrictions under the Civil Aviation Act 1982 section 78 is 2300-0700. This is also the default recommendation contained in the END (Annex I). The methods to be used to generate noise levels in these indicators are discussed in the appropriate source chapters (Chapters 5, 6, 7 and 8).

3.16. To maximise the usefulness of the results obtained from the END noise mapping process, it is also proposed to secure noise level information in terms of indicators that are in common use already in Scotland. As L_den is a new indicator and current legislation and policy guidelines are based on other indicators there is little benchmarking available for L_den compared to other indicators. The following table shows the indicators we propose to obtain for each of the noise sources:

Acquisition of data to make maps

3.17. As explained in paragraph 3.5, a large amount of data will be needed to produce the noise maps. There are three main types of data that will need to be collected – noise source and geographical data to run the models, and population data in order to calculate population exposure. Specific data requirements differ between the different noise sources and these are explored in more detail in each of the noise source chapters (5, 6, 7 and 8).

3.18. The Scottish Executive believes that the majority of the data needed to produce noise maps to meet the requirements of the END is available to them from existing Scottish Executive databases and through existing commercial arrangements. Should there be instances when such sources prove inadequate or too expensive the Scottish Executive proposes to generate data using the recommendations within the WG-AEN GPG (See paragraph 2.23).

Maps required by END

3.19. Article 1 (1) of the END specifies three actions to support the objective of the END. Mapping is critical for each of the actions:

• to inform the Commission of noise exposure across Europe;
• to inform the general public of the noise climate within the Member State; and
• to act as a basis for the development of action plans.

The mapping data to be sent to inform the Commission are outlined in Annex VI of the END. It is understood that the Commission may issue further guidance on the data it requires and the format in which this data needs to be supplied at a later date through a recently commissioned study: ‘Preparation of a reporting mechanism under Directive 2002/49/EC relating to the assessment and management of environmental noise’.

Accuracy of maps

3.20. Having identified the methodologies that are going to be used to generate the maps, the accuracy will be affected by the availability and quality of the input data used. The Commission’s WG-AEN has issued some guidance providing advice on assumptions that can be made regarding input data²⁰. No advice has yet been received on the required accuracy of the maps. However, the WG-AEN is examining this issue as part of its terms of reference for 2004/5. In the meantime, the Scottish Executive will have to make a judgement in balancing the cost of obtaining very accurate input data against the benefit that this could achieve, bearing in mind that the main purpose of the process is the production of strategic maps but that these must provide a sound basis for developing action plans.

3.21. It is anticipated that an acceptable level of accuracy at the strategic level might not precisely represent every situation at a local level. It is likely that more detailed examination will be necessary in some of these situations in order to develop the local elements of action plans. This will be a matter for those tasked with the preparation of the plans but the Scottish Executive hopes to provide guidance in this respect.

Co-operation at administrative boundaries and the edge of maps

3.22. As the END will be implemented separately in England, Wales, Scotland and Northern Ireland, it will be important for those different administrations to consult with one another to ensure that the maps produced are compatible where there are cross-border noise issues. In Scotland’s case this will mean consultation with administrations in England. We will need to consult them, and vice versa, on roads and rail which cross or adjoin borders. However, it is unlikely that consultation between England and Scotland on airports and agglomerations will be necessary as they are not expected to give rise to cross border issues.

3.23. The results from noise mapping across the UK will be collated centrally by the UK Scottish Executive so that the information required by the END can be submitted to the European Commission and made available to the public as a whole.

Review of noise maps

3.24. The END requires that the production of strategic noise maps for major roads, railways and agglomerations should be an ongoing process with maps being made every five years following the first round of mapping in 2007 (Article 7 paragraph 2). Maps for relevant airports must be reviewed and revised if necessary, at least every five years after the date of their preparation (Article 7 paragraph 5). The END also requires that action plans be reviewed, and revised if necessary, at least every five years following the first round of action planning in 2008 (Article 8, paragraph 5) but also that they be reviewed and revised if necessary when a major development occurs.

3.25. To comply with the END, the Scottish Executive proposes that, as the action plans must be based on noise maps, that the maps for all sources (including airports) should also be revised at least every five years but also that they (or parts of them) should be reviewed (and revised if necessary) in the intervening period if a major development occurs – in order that they should support the action plans which must be revised in such an instance (Article 8, paragraph 5).

3.26. The Scottish Executive proposes that the trigger for that review (and potential consequential revision) would be a significant change from the results set out in last published noise map. A significant change is one that could potentially result in a change to a published action plan. Ideally the review and any subsequent revision should be carried out by the organisation or authority that carried out the mapping originally.

Q3.2: Do you agree with the proposed trigger for the review of noise maps outside the five year cycle?

Q3.3: Do you believe that it would be possible to establish a level change in decibels at which a change could be viewed as significant. If so what should that level be?

Finalisation of maps

3.27. This document refers to an approval process. In the context of mapping, this is the mechanism whereby it is made clear when the legal duty to produce a map has been adequately discharged. If the Scottish Ministers are named as competent authority for the preparation of the noise maps, this approval will be an integral part of the preparation process.

3.28. If the Scottish Ministers are not the competent authority (as proposed for non-designated airports, - see Chapter 7) the Scottish Ministers will instead be designated as competent authority for the collection of maps. This collection function will include ensuring that the competent authorities have adequately discharged their responsibilities. Only then will the Scottish Ministers submit the maps to the European Commission.

Presentation and availability of noise maps

3.29. Annex IV of the END sets out the minimum requirements for strategic noise mapping. It also sets out a number of options for the type of noise map that can be prepared, along with options for the presentation of the results of noise mapping both for the purposes of sending data to the Commission and presenting the information to the public. These are set out and discussed below:

Presentation of data to the Commission

3.30. Annex VI of the END (See Annex A to this document) sets out requirements for noise mapping data to be sent to the Commission. Given these information requirements, we propose to send noise mapping data to the Commission in the form of numerical data in tables.

Presentation of data to the public

3.31. Annex IV of the END gives examples of the type of noise mapping information that can be given to the public in order to comply with Article 9 which requires that the noise mapping data (additional to, and more detailed than, that required to be sent to the Commission) must be made available to the public, such as:

• a graphical presentation (also known as noise contours);
• difference maps in which the existing situation is compared with possible future situations;
• maps showing the values of a noise indicator at a height other than 4m where appropriate;
• the estimated number of dwellings, schools and hospitals in a certain area that are exposed to specific values of a noise indicator;
• the estimated number of people located in an area exposed to noise.

3.32. We propose in the first instance to produce maps showing noise contours, along with tables showing the estimated number of dwellings, schools and hospitals in a certain area that are exposed to specific values of a noise indicator and the estimated number of people located in an area exposed to specific values of a noise indicator.

Q3.4: Do you agree with the proposal to make noise mapping data available to the public in the form of tabulated numerical data and maps showing noise contours?

3.33. It is proposed that even in cases where maps are not produced by the Scottish Ministers they will be collected centrally by Scottish Executive for transmission to the European Commission. The Scottish Executive therefore proposes to make the maps and data publicly available electronically from a central database. This is most likely to be the Scottish Executive website. For those who do not have access to the internet, it is proposed to make noise maps available on CD-ROMs which can be held for reference at public libraries and/or local authority offices. Hard copies will also made available by post for a reasonable charge through application to Scottish Executive.

Q3.5: Do you agree with the proposal to make noise mapping data available to the public through the Scottish Executive website and CD-ROMs?

Timescale for making maps

3.34. Article 7 paragraph 1 of END requires that the first round of noise maps be made and (where relevant) approved or collected by 30 June 2007 for the preceding calendar year. Strategic noise mapping, to the standard required by the END is a complex exercise. We cannot exactly predict, at this stage, the length of time that it will take to carry out the mapping but we estimate that, for some sources, it may take as much as 12 months. It may therefore not always be possible to start mapping on 1 January 2007 using data for 2006 if it is clear that we will not be able to finish mapping in time for the 30 June 2007 deadline. Therefore the Scottish Executive proposes that, if necessary, mapping should be started during 2006 using some 2005 data - Article 5, paragraph 1 allows this.

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