The project supported the European noise policy to eliminate harmful effects of noise exposure and decrease levels of transport noise creation. Especially in urban areas. CITYHUSH derived solutions that will ensure compliance with the constraints of legislative limits.
The project supported city administrations in the production and implementation of noise action plans according to the current directive (EC 2002/49).
The objective was to provide municipalities with tools to establish noise maps and action plans and to provide them with a broad range of validated technical solutions for the specific hot-spot problems they encounter in their specific city. The identified hot spots and noise acting plans made with the existing technology suffer from major shortcomings:
- poor correlation between hot spots with annoyance and complaints;
- most measures lead to increased emissions;
- only indoor noise comfort is addressed.
Step change solutions were proposed to reduce noise in the city environment. The project dealt with developing suitable problem identification and evaluation tools. And with designing and developing solutions for hot spots, which show high correlation with annoyance and complaints. The following innovative solutions and tools were developed:
- Concept of Q zones (zones where only quiet low emission vehicles are tolerated);
- Concept of parks embedded in Q zones;
- Improved noise score rating models (for indoors) by integrating low frequency noise and the occurrence of high noise single events;
- Noise score rating models (the outdoors);
- Objective and psychoacoustic evaluation tool for low noise low emission vehicles;
- Mathematical synthesis tool for noise from low noise low emission vehicles;
- General performance noise specifications for low noise low emission vehicles;
- Novel concepts for low noise roads based upon dense elastic road surfaces;
- Novel concepts for low noise roads based upon grinding of asphalt top layers;
- Novel concepts for tyres for low noise vehicles, including heavy vehicles;
- Criteria for use of low noise motorcycles;
- Active and passive noise attenuation measures within the tyre hood;
- Solutions for high low frequency absorption at facades of buildings;
- Solutions for high low frequency isolation in the propagation pad.
All the above solutions and tools were designed, prototyped and validated. They resulted in attaining the anticipated noise impacts.
The following technical tools and solutions have been studied and developed:
- Indoor noise score rating models, which correlate better with annoyance and noise complaints by integrating low-frequency noise and the occurrence of high noise single event (e.g. passing motorcycles) into the analysis;
- Noise score rating models for the outdoors in order to be able to assess the complete living and working environment;
- Mathematical synthesis tool for noise from low-noise / low-emission vehicles to be used in simulation studies;
- Objective and psychoacoustic evaluation tool for low-noise/low-emission vehicles;
- General performance noise specifications for purchasing low-noise/low emission vehicles and noise criteria for acceptance of vehicles within the Q-Zones;
- Novel concepts for low-noise roads based upon dense elastic road surfaces;
- Novel concepts for tyres for low-noise vehicles, including heavy vehicles;
- Criteria for use of low-noise motorcycles within a city environment using a holistic approach taking into account benefits in terms of congestion reduction and other;
- Solutions for noise mitigation based upon high / low frequency absorption at facades of buildings. Prototypes have been made and laboratory testing is being carried out.
- Solutions for noise mitigation based upon efficient low-frequency isolation in the propagation path to reduce ground borne noise. The scaling factor for the tests and the test bench was determined and the test bench and the measurement set-up for the simulations validated.
Interest in the project results comes from:
- Experts from local and regional authorities responsible for urban development, traffic, public health, and environmental issues: these experts are interested as the CITYHUSH results provide guidance and tools on how to assess and reduce/solve noise problems in cities.
- Decision makers from local, regional, national, and European authorities: their interest is that the results make them aware of the noise problems in cities and the possible solutions.
- Vehicle manufacturers: these stakeholders are interested in the results as these provide new insights into low-noise solutions for urban road traffic noise, for example the benefits of new low-noise tyres.
- Road authorities: these stakeholders is that the results provide new insights into low-noise solutions for urban road traffic noise, for example the benefits of new low-noise road surfaces.
- Research institutes, consultancy firms, and other organizations active in the area of urban development, traffic, public health, and environmental issues: the project results provide new insights that should be taken into account in noise assessments and health impact assessments, which these stakeholders perform for various clients.
- Research networks, such as ENNAH1 and ERTRAC2: the interest of the research networks is that the results are of interest for the partners of the networks.
- General public: the results may provide solutions for noise problems of inhabitants of a city, and that they may provide more information on the relevant noise levels affecting citizens.
- Innovating for the future (technology and behaviour): Promoting more sustainable development