Noise walls are constructed along the highways and roadways to protect adjacent residents from the adverse effect of noise from road traffic. Although most noise walls in United States are made of concrete, other materials are also available and newer materials are being introduced. However, no uniform standard has been maintained by the material manufacturers and vendors regarding the acoustical effectiveness of these materials. Additionally, there has been no available benchmark to evaluate different materials with respect to the existing concrete noise walls in terms of reducing traffic related noise.
In response to this, the research team has systematically evaluated available materials for noise walls and their corresponding industry acoustical standards, analyzed various acoustical methods, collected and analyzed field data, and created a guideline to assist NCDOT in selecting and approving noise wall materials.
