How can we plan for a good urban sound environment, focusing on road traffic noise?

Abstract

Introduction. The sound environments in our cities are affected by unwanted sounds, i.e. noise, to an extent that is largely undesired, affecting health and wellbeing. The World Health Organization (WHO) has estimated the burden of disease from traffic-related noise within the western part of Europe and concluded that we each year lose at least one million disability-adjusted life years (DALYs) and that only air pollution has a larger disease burden among environmental factors. The burden of environmental noise is mainly sleep disturbance and annoyance. And the dominant source is road traffic.Methods. This paper describes the mechanisms behind road traffic noise and how we can use them in an urban sound planning perspective to improve the sound environment, as an integral part of sustainable cities and communities. The results are based on calculations and measurements made in previous and ongoing projects.Results. Treatments at source consider tyre, road, engine (whether electric or combustion), driving speed and acceleration, and further vehicle restrictions. Methods for reduction of noise during propagation and more general urban planning aspects include low-height barriers and ground treatments; acoustically absorbing facades and roofs of buildings, e.g. including vegetation; and building morphology and quiet side. Quantitative reductions, in decibels, as well as qualitative aspects are presented.Conclusions. The described possible improvements to the urban sound environment, with focus on road traffic noise as the dominant impairing factor, inform us about how a good urban sound environment can be reachable. However, to reach a good sound environment in reality, the work process of applied urban sound planning demands work across disciplines, also at early-stage planning, instead of traditional noise control applied late in the planning process.