This study provides a comprehensive review of noise climate assessment activities in the UK and in six other EU countries. The review has been carried out to provide information that can help in considering future noise mapping activities in the UK. Section 5 of this report provides an analysis of the review findings and forms a summary of the study. From this the following conclusions can be drawn.
6.1.1 Noise Mapping in Mainland Europe
- Noise mapping in Europe has reached a high level of sophistication in recent years, partly as a result of increased activity in response to the targets set in the Fifth Environmental Action Programme in 1993.
- Noise modelling, for assessing noise climate locally in connection with particular projects, has offered an accurate way of assessing noise climate on a small scale for many years, but it is only recently that techniques have been developed to cover wider areas in order to consider population exposure to noise in a far broader way.
- Noise mapping techniques are now in use at city or town level, and also at national level for road and rail networks. Progress in computer-based systems for manipulating information on population density, traffic patterns and mapping have allowed city-level noise maps to give a fairly detailed picture of the urban noise climates of several cities, for example in Germany, Netherlands and Austria.
- There are variations in approach to the main stages of noise mapping: generation of noise data, the area mapped, the type of information presented, and the manner of presentation.
6.1.2 Activities within the UK
- Noise mapping activities in the UK are less developed; the ISIS project and the work in connection with the National Transport Model are the principal areas of activity.
- The review of local authority practices has shown that local authorities generate large amounts of environmental noise data, but these are generally not in a form that is useful for noise climate assessment at the national level.
- The exclusive use of measured data for assessing population exposure to noise would preclude the system from being predictive. It is clearly desirable that a system for estimating population exposure to environmental noise should be predictive in order to allow the effects of influencing traffic patterns through new transport or environmental policies to be tested.
- Measured data may be best suited to non-transport noise sources such as industry and leisure (which are inherently unpredictable), and for validating a predictive system.
In view of experience from the rest of Europe, and the information generated within local authorities, it appears that the four types of noise mapping could be combined. This may be the most reliable and cost effective approach to assessing population exposure to environmental noise across the UK. The four elements are:
- A strategic traffic noise mapping system will be valuable if national policies on road and rail traffic are to be tested for their effect on overall population exposure;
- GIS-based noise modelling at a city or town level would be required to refine the level of accuracy, and could be limited to selective key areas;
- Annoyance Mapping could be investigated to help identify key areas of exposure to environmental noise, and to make the system more accountable to the public; and
- Measured Data Mapping could also be used as it is probably the only technique available for certain inherently unpredictable noise sources such as industry and leisure activities.
The consultant has outlined a framework in which these four types of noise mapping could be combined in order to allow a realistic analysis of the UK population exposure to environmental noise. Such a system is seen as a first step to developing an action plan to assess, and if necessary improve, the noise environment of the country, as proposed in the Fifth Environmental Action Programme.
6.1.3 Conference on EU Noise Policy
The consultants gave a presentation a recent conference on EU Noise Policy (1) that included a special session on noise mapping and other matters relevant to noise mapping.
The other presentations at the noise mapping session reinforced the above findings both as to the effort put into noise mapping in some other EU countries, and the diversity of approaches. The conference also addressed other noise issues related to noise mapping and relevant conclusions drawn from those aspects are summarised below.
- The cost of data gathering and inputting for noise mapping can be greater than the cost of the software and hardware systems used to implement it.
- Some fundamental questions need to be resolved before noise effects can be determined. For example, there was a strong view that the night-time period should be considered separately from the daytime. However, owing to cultural and geographical differences, the hours of day and night would need to vary across the EU.
The scope of noise mapping is not universally accepted. There is a view that 'domestic noise' is not an appropriate or suitable source for noise mapping. However, in urban areas this source of noise accounts for a substantial proportion of complaints(2,3). This topic can also be addressed by noise policy. For example, the Noise Act 1996 has been passed, and some UK local authorities have set targets for reducing the number of noise complaints as part of an overall strategy towards improving environmental quality in their areas.
Other topics that relate to the scope and presentation of noise maps are:
- In urban areas the noise exposure of buildings can vary considerably between the 'exposed' side (where a good standard may not be achieved) and the 'quiet' side (where the situation may be acceptable or a good standard). These differences may not be apparent from a noise map.
- It is considered important to designate, protect, and develop 'quiet 'areas or zones in both urban and rural areas. There is some doubt, however, as to whether noise mapping is able to identify such areas with sufficient accuracy.
The results of this review suggest that there are four main areas of work that could be considered in order to develop a system for estimating the UK population exposure to environmental noise:
- developing selective city-level road and rail traffic noise models;
- assimilating local authority measured data;
- noise exposure modelling derived from the National Transport Model; and
- developing a central system to guide and co-ordinate these three areas of work and to combine their outputs.
The ISIS project could be taken forward to address the first of these. Alternatively, experience from other European countries could be investigated. However, differences in the level and formats of available input data could limit their transferability.
It is possible that further technical work under the auspices of the EU may be carried out in some of the areas which emerged at the Hague Conference as unresolved. It is considered important to be involved with any such work.
1 May 21 and 22 1997, in The Hague, organised by the Dutch Ministry of the Environment
2 According to figures published by the Chartered Institution of Environmental Health Officers, it is the major source of noise complaints in England and Wales.
3 The high number of complaints does not necessarily indicate that domestic noise is the major source of noise exposure.
Published 1 June 1999
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