Applications - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 283

Urban noise management means to reduce the level of unwanted noise or to
mitigate the noise sources (planting trees, building sonic barriers, etc.).
Sonic barriers, either composed of plastic, concrete, or living materials, also
reduce and degrade the scenic composition of a urban landscape. Technical
solutions adopted on cars, trucks, and trains can reduce traffic noise. For instance,
electrical engines can greatly reduce traffic noise.
Rolling noise is produced by tires and by the road surface, and a road well
maintained reduces this rolling noise. Railway noise is mainly produced by the
friction between metal surfaces of rail and wheel. Relevant improvements are
possible especially for freight; noise barriers are significant solutions but not in
urban areas because of space restrictions and visual impact.
The reaction of people to noise exposure depends on many factors. For instance,
noise annoyance is higher for the same energetically averaged exposure for aircraft
noise than for traffic noise. This is the same for industrial noise; a marble sawmill in
Carrara City (Italy) is at the same time a soundmark for residents and a source of
annoyance for visitors.
Indoor noise mitigation from outdoor noise sources is easily achieved using
insulating materials and closing doors and windows, but these actions can create a
sense of claustrophobia for dwellers and a negative effect on perceived annoyance.
10.15 Traffic Noise Mitigation Procedures
and Urban Spaces
Orchestrating traffic noise represents a realistic opportunity to improve the sonic
ambience in urban spaces. Traffic is the result of a flux of cars, trains, autobuses,
and trucks. Direction, intensity and fluxes may be changed. For instance, the
substitution of roundabouts for traffic lights can modify cyclic noise by reducing
acoustic peaks after the lights turn green.
Traffic dynamics is under two main scaling constraints: a large scale that largely
depends on the quantity of vehicles and their direction and speed and a microscale
largely impacted by personal style in driving. The microscale modeling of traffic
allows simulating every individual behavior that creates emergent phenomena such
as traffic congestion. The noise emission coupled with individual behavior creates
the conditions for overall traffic noise. Acceleration and deceleration near
intersections are important components of traffic noise, and modeling close to
intersections is an important component.
Noise redistribution and noise reduction are two different strategies for manag-
ing traffic. To create a quiet area in a city is possible by removing traffic, but such
traffic may create congestion elsewhere, and increased noise, so in terms of overall
noise impact on the city the redistribution of traffic is a local remediation but not a
holistic solution strategy.
The effect of highway construction on the urban setting produces changes or
“sonic fields migration.” This effect was studied by Ramis et al. ( 2003 ) in the town