The following sections give an overview of the approach to the European review and the UK review, but first it is helpful to set the scene by summarising some other studies that have (or are currently) addressing similar subject matter.
The Fifth Environmental Action Programme has triggered a number of studies concerning noise mapping. It is not considered appropriate to describe these in detail as part of this review but the reader should be aware of some of the key recent or ongoing studies for reference, as required.
In November 1995 the European Commission published a draft proposal for a Directive on Ambient Noise Exposure Assessment. The Commission is encouraging work on noise mapping and has held a number of workshops to discuss its recent Green Paper and noise mapping issues. The workshop on 24th March 1997 entitled Urban Noise - Tools for Diagnosis and Perception included a half-day session on noise mapping. The Consultant attended this workshop and has included in this report comments on the relevant material presented.
The European Environment Agency has commissioned a study entitled Ambient Noise Levels and Exposure to progress the unification of noise indices across Europe. In relation to this work the Danish Environmental Protection Agency produced a report in January 1997 entitled Danish experience in monitoring noise exposure, and necessary steps towards procuring data for a uniform European mapping of environmental noise.
At the end of 1996 the UK Department of Transport commissioned a Feasibility Study for the Development of Environmental Modelling in Connection with a National Transport Model. The study concerns noise and air quality impacts from road, rail and air transport across the UK. Although we are not aware of the current state of progress, the subject matter raises the prospect of a national environmental transportation noise model. Such a model could play a central role in quantifiably mapping the exposure of the UK population to environmental noise, all-be-it at a low level of detail. The issue of prediction versus measurement of noise, and the balance between the two, is a recurring theme in the rest of this report.
In February 1994 a study entitled ISIS (Integrated System for Implementing Sustainability) was commissioned under the European Community 'LIFE' programme. The project was given a budget of just over 2,000,000 ECU (approximately £1,400,000) and was undertaken in collaboration between four partners; Kirklees Metropolitan Council (UK); Senatsverwaltung für Stadtentwicklung, Umweltschutz und Technologie (City of Berlin); Miljøkontrollen, Agency of Environmental Protection (City of Copenhagen); and Laboratório Regional de Engenharia Civil (Regional Government of Madeira). The work is nearing completion and we are grateful to Kirklees Metropolitan Council for providing an overview of the results including an advance copy of the Noise Guide .
The ISIS project was aimed at providing guidance for policy makers, decision makers and administrators at local authority level, on dealing with and planning for road traffic in their area. Air emissions, noise emissions, traffic safety and energy use were mapped and analysed to provide sustainability maps for sample urban road networks. Kirklees was the lead partner in this project. One of Kirklees' roles was the development of a decision support system which integrated the work from various parts of the project on a GIS platform. The work undertaken on the ISIS project is therefore relevant to this review and a summary of the key findings with regard to noise mapping follows with relevant sample outputs provided in Annex A.
Within ISIS, traffic noise levels are modelled from traffic data generated within the local transport model using the Nordic Norms(1). By applying a standard road to receiver distance (eg 10m), and a simplistic propagation model, noise levels are assigned to each link of the major road network. Each link is represented by colour coding according to its noise level range (and therefore sustainability score) and the coloured links are overlaid onto the city map base. In this way areas of high (potentially unsustainable) noise are shown and can be tested under different traffic and urban planning scenarios. The sustainability scores for noise are integrated with the scores from the other sustainability indicators to produce the overall sustainability map, and thus ISIS achieves its aim. The Kirklees team have, however, tried to take the noise mapping several stages further with the assistance of the University of Huddersfield.
In a typical urban setting the propagation of traffic noise from the road to the receiver is generally over a short distance and, although complex screening and reflection effects can occur, a good approximation of noise levels at the nearest facades to the road can generally be estimated from simple assumptions of unrestricted propagation over an estimated distance. The situation in a more rural setting is harder to approximate because distance, screening and ground absorption effects become more important. The Kirklees team addressed this problem by constructing a GIS-based noise model for a small case-study area.
The study area was the Marsh district, bisected by the A640 west of Huddersfield (see figures in Annex A). The major road network was digitised and traffic flow data was used to generate basic noise levels for each road link. The land cover in the region was categorised using standard planning classifications, eg very low density housing, green space, industry. Each land cover category was assigned a simplistic noise screening value (0, 10 or 20 dB(A)), and ground absorption value (up to 12 dB(A). These land cover noise reductions were then applied to the basic noise levels to arrive at a zoned noise map of the area. A brief validation exercise by noise measurement showed that the results were promising. Clearly there is scope for this modelling technique to be further refined. Whilst accurate traffic noise modelling in rural situations is not new, placing this model on the GIS platform means that estimating population exposure from census or post-code population data would be relatively simple.
Later sections of this report describe how GIS noise mapping and exposure models have been developed extensively for urban areas in other countries. This ISIS work demonstrates that the methodologies can be extended to allow for the more varied rural situation.
2.3 Approach to European Review
Six countries were selected for detailed review. The selection criteria were broadly as follows:
- to include the most active countries;
- to maximise geographic, cultural and political spread; and
- to make use of existing contacts that would lead to high quality information.
Preliminary inquiries were made to investigate the level of noise mapping activity in each country through the network of ERM European offices and other contacts across Europe. The coarse level of information gathered in this way is reported in Section 3.1. This process arrived at the following selection:
- Austria;
- Denmark;
- France;
- Germany;
- Netherlands; and
- Spain
Having selected a representative sample of six countries, the approach to the review of European practice was to to establish contacts in the relevant government departments and carry out interviews to obtain the required information. The interviews were supplemented by communications by fax, e-mail and post.
Each interviewee was sent an introduction to the project and an agenda in advance, and it was generally possible to carry out the interviews in the interviewees' native language to ease the flow of information. The findings for each country were written up and sent to each country representative for comment.
The approach to the review of UK practice was slightly different because there were far more authorities to investigate, but it was anticipated that many similarities would be seen between groups of authorities. It was decided at the outset that it was important to investigate any local authority that was operating a particularly interesting or innovative noise climate assessment system and thus it was necessary to contact every one. A three stage approach was therefore developed.
In Stage 1, a simple questionnaire was developed and sent to all 460 County Councils, Unitary Authorities, District Councils, Metropolitan Borough Councils and London Borough Councils. The returned questionnaires were analysed to develop a 'long-list' of potentially interesting authorities, and to provide a general impression and some overall statistics on noise climate assessment practices.
In Stage 2, the 27 long-listed authorities were contacted to provide more detailed information based on the questionnaire subject matter. This process revealed further useful findings and led to a short-list of six to eight authorities that were visited and interviewed in Stage 3.
1The Nordic Norms form a group of noise predictions standards that are used across the nordic countries, i.e. Norway, Finland and Denmark
Published 1 June 1999
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