Noise barriers are the most effective method of mitigating roadway , railway, and industrial noise sources – other than cessation of the source activity or use of source controls. In the case of surface transportation noise, other methods of reducing the source noise intensity include encouraging the use of hybrid and electric vehicles , improving automobile aerodynamics and tire design, and choosing low-noise paving material . Extensive use of
Noise barriers began in the United States after noise regulations were introduced in the early 1970s.