Reducing noise in cities
Air pollution and noise pollution researchers combined forces to create the concept of Q-Zones — areas in inner cities where only quiet, low-emission vehicles are allowed. The EU-funded project 'Acoustically green road vehicles and city areas' (CITYHUSH) sought to empower cities to create Q-Zones with noise levels reduced by over 20 decibels, and parks within these zones where current noise levels would be reduced by 25 decibels. Five test cities reflecting different noise and traffic models in Europe were used to determine boundary conditions needed to achieve Q-Zones, as well as boundary conditions and maximum noise gains for parks embedded in these zones. To achieve its aims, the project redefined indoor and outdoor noise rating models that determined the percentage and number of residents annoyed by noise in a given area such as streets and parks. Researchers developed several tools for low-noise vehicles and road surfaces, as well as noise barriers. They assessed the noise from low-noise and low-emission vehicles to produce accurate psycho-acoustic noise maps. This also involved outlining noise specifications for purchasing these vehicles and for allowing them into the city. The team developed a tool to measure road roughness, as well as strategies for low-noise roads based on dense elastic road surfaces and low-noise tyres. It established criteria for use of low-noise motorcycles within a city environment. Project partners also evaluated the potential of noise reduction by new tyre hood technology, as well as design solutions for building facades and noise barriers to mitigate low-frequency noise. CITYHUSH envisions quiet cities for the urban environment of tomorrow. Its proposed solutions and tools for tackling transport noise problems should ultimately help European city dwellers live better lives.
Keywords
Road vehicles, inner cities, noise pollution, Q-Zones, city areas
