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Quieter surface transport

Exploitable results

For decades, European policy-makers have concentrated on regulating noise emission from sources such as road and rail vehicles, aeroplanes and other equipment by fixing maximum sound levels, which has resulted in significant noise reduction from individual sources. For example, noise from individual cars has been reduced by 85 % since 1970 and noise from trucks by 90 %. However, no consideration has been given to reducing noise emission in urban areas and for some sources, such as railways, there was no EU legislation setting noise creation limits. As a result of this, and in response to the regulatory gap, the Commission Directive 2002/49/EC, relating to the assessment and management of environmental noise, was adopted. Its main aim is to provide a common methodology to address noise problems across the EU and it is in this context that the activities of Silence are to be seen. The following results have been achieved within the different activities of the project: 1. Noise perception and annoyance evaluation of traffic noise reduction - Various traffic noise scenarios have been analysed out of source libraries; - Annoyance of residents in different EU cities and countries have been determined in combination with noise maps; - Guidelines and targets for annoyance reduction have been defined. 2. Development of a global modelling tool for vehicle exterior noise emission - A global modeling tool has been developed and validated for rail and road vehicle exterior noise; - Source models and noise sources have been defined and characterised; - The model has been validated also with respect to annoyance. 3. Noise reduction of tyre-road interaction - Low noise tyre-road combinations have been investigated under urban traffic conditions; - Simulation tools for tyre noise have been developed; - Vehicle concepts for tyre noise suppression have been defined with respect to development of advanced noise reduction technologies, methodologies and software tools for urban road vehicles. 4. Experimental- and simulation tools for road vehicle noise reduction - Advanced simulation tools for vehicle noise source reduction have been developed; - Experimental noise source identification methods have been set up and validated; - Advanced noise reduction technologies and materials, based on damping and absorption have been demonstrated in hardware. 5. Noise reduction of rail vehicles in urban areas - Noise source ranking of rail platforms for definition of the noise reduction potential; - Low noise diesel power-pack systems including cooling and auxiliary systems have been developed; - Measuring campaigns for noise reduced traction equipment and running gear have been performed. 6. Design and maintenance aspect of low noise road surfaces - New production technologies of quieter road surfaces have been developed; - Acoustic effects of new road surfaces at tyre - road interactions have been optimised; - New low noise road surface materials have been tested; - Systems for maintenance of low noise roads have been investigated; - Noise classification methods for urban road surfaces have been defined. 7. Noise reduction of rail infrastructure and for rail operation at 'hot spots' in urban areas - Definition of low noise tracks for trams, metros and railways in urban areas; - Noise reduction concepts with respect to rail roughness and damping aspects; - Acoustic models for train depots have been developed also with respect to annoyance. 8. Management techniques for road traffic flow noise reduction - Methods for noise control by traffic management and driving patterns have been developed; - Roadside traffic monitoring systems have been investigated for noise reduction of traffic flow; - Evaluation of driver assistance systems for quiet vehicle operation; - Assessment of driver acceptance by questionnaires have been performed; - A toolkit for city authorities is available. 9. City planning with respect to noise abatement - Urban noise scenarios have been evaluated and defined; - Analysis of noise perception in urban areas (soundscapes) has been conducted and definition of measures for better urban design has been developed; - Urban action plans have been defined; - Decision support systems for cities have been developed. 10. Dissemination and training of the silence results to cities and industry - Silence newsletters; - Updating of the Silence website; - Silence seminars for cities and industry; - Promotion of Silence at several events; - Training of researchers and engineers. With a combination of the individual results of Silence, a reduction of urban noise emission from surface transport by up to 10 dBA is feasible in the near future.