A major environmental problem within the EU is noise pollution. The social costs of traffic noise have been estimated to 0.4% of total GDP. Road traffic is the dominant source, and also rail traffic noise is significant. At the same time, road and rail traffic are expected to steadily increase, and the source strength is not expected to significantly decrease within the near future. To reduce the outdoor traffic noise to a sufficiently low level for a good acoustic environment is a major challenge. In HOSANNA the focus will be on noise propagation abatement for the outdoor environment.
Following the EU Directive on environmental noise, a series of major actions have been taken in noise abatement. However, to sustainability rarely attention has been paid. The main idea of HOSANNA was to optimise the use of green areas, green surfaces and other natural elements in combination with artificial elements in urban and rural environments for reducing the noise impact of road and rail traffic.
The main objectives of the project are: (i) to show by full scale evaluation that the proposed abatement methods work, (ii) to deliver noise prediction methods applicable to the proposed abatements, which can also can be used in noise mapping software, (iii) to deliver assessment methods for the perceived noise environment, (iv) to deliver a good practice guide for the end-users, and (v) to show the cost benefit, including the positive effect on urban air quality and CO2 neutrality, of the resulting noise abatement methods.
HOSANNA set out to:
- Develop new, powerful and sustainable abatement methods for noise reduction, based on natural means in combination with artificial means;
- Show by full-scale evaluation that the abatement methods work;
- Develop prediction methods applicable to analysis and design of the developed abatements;
- Make available simplified models applicable to the developed abatements, which can be used in engineering noise mapping software and make our innovative approaches show in reporting of strategic maps and action plans to the EU;
- Make available assessment methods for the perceived improvement of the sonic environment and reduced noise annoyance;
- Show the cost benefit of the resulting abatement methods, including the positive effect on urban air quality and CO2 neutrality and to
- Disseminate the results to the user community (consultants, local authorities and planners), mainly by producing, making available and presenting a good practice guide.
The project offered a variety of powerful abatement strategies that will make a cost effective improvement by its combination of approaches concerning:
- ground and road surface treatments;
- trees, forests and tall vegetation;
- greening of buildings and other surfaces and
- innovative barriers.
The noise impact was assessed in terms of sound levels (including spectra and time patterns) as well as perceived environment (including annoyance, well-being and other health related aspects).
The project has presented better ways of using vegetated surfaces and recycled materials to reduce road and rail traffic noise and to improve the perceived sound environment.
A toolbox has been developed, containing a large variety of measures. Traffic noise situations are often complex and a single noise mitigation measure is seldom sufficient. Some of the tools proposed each lead to 2–3 dB(A) in noise reduction. Thus, an appropriate combination of measures is needed to obtain a larger effect.
Other noise abatements from the toolbox individually reduce noise by 10 dB(A) or more. Most of the estimated noise reductions have been calculated using advanced numerical methods, rather than measured in real situations. Therefore a small uncertainty is expected in real situations. To minimise this uncertainty, the estimation methods have all been validated and are applied in situations that are as realistic as possible. In addition, the impairment in performance due to meteorological effects has been estimated for selected cases by modelling the effects of mean wind and turbulence.
The project encourages the implementation, and further development, of the suggested green noise abatement methods. A handbook with detailed information will be published in late 2013.
Innovating for the future (technology and behaviour): Promoting more sustainable development