Arenas J.

In particular, noise barriers are a commonly used measure to reduce the high levels of environmental noise produced by the traffic on highways. Nevertheless, single screen barriers are also widely used in open-plan offices to separate individual workplaces in order to improve acoustical and visual privacy. When developing environmental impact studies for highways, it appears that construction of barriers is the main alternative used for the reduction of noise, although quiet road surfaces, insulation of properties or use of tunnels have also been used for this purpose. In the design of a barrier all of the relevant environmental, engineering and safety requirements have to be considered. However, in addition to mitigate the impact of a highway, a barrier will become part of the landscape and neighbourhoods. The public, increasingly well-informed about the problem of excessive noise, is taking actions on the development of new transport infrastructure projects and improvement to existing infrastructure.Therefore, particular consideration has to be taken to assure a positive public reaction from both residents adjacent to barriers and drivers. In this keynote lecture a review of some fundamentals of the theory of the diffraction at the edge of a plane barrier will first be considered as the basis for all applications and the development of prediction algorithms.Then, use of barriers indoors and outdoors will be presented. Finally, some additional concepts for the design, economics, materials, construction details, aesthetic, and durability will be discussed.