How does a noise wall work?
Noise walls reduce highway traffic noise from entering adjacent neighborhoods by reflecting or diffusing the noise. To achieve the maximum noise reduction possible, a noise wall must be tall enough and long enough to block the view of a highway from your home. How does WSDOT decide where to build noise walls? WSDOT considers constructing noise walls for two scenarios: • Scenario 1: WSDOT considers constructing noise walls in neighborhoods that will experience an increase in traffic noise after the completion of a state highway project, such as a new road widening project. Design and construction of these walls are added to the scope and budget of the highway project to reduce the overall effect of increased traffic noise on the surrounding community. • Scenario 2: Noise walls are also considered for neighborhoods that were developed prior to May 14, 1976 that are adjacent to major freeways currently experiencing a high level (66 decibels or higher) of noise. At 66 decibels (dBA), most
