Community noise countermeasure cost-effectiveness analysis

Abstract

An analytical model of a typical community has been developed for the purpose of carrying out a cost-effectiveness analysis of various outdoor noise countermeasures. The principal elements of the model are (1) a data base describing the community's geography, population distribution, and typical building construction: (2) a data base describing the location and strength of noise sources; (3) energy summation of noise levels from each source at many locations; and (4) use of noise level versus human response transfer functions to determine the number of people adversely affected by noise level. Summing these for the whole community and dividing by the total population results in a “Noise Impact Index (NII)” indicating the quality of the noise environment. Three basic types of countermeasures may be applied: (1) source reduction, (2) source rerouting, and (3) path-receiver treatments (increased building attenuation, relocate people). Each countermeasure is also defined in terms of the corresponding costs to achieve varying amounts of noise level reduction. Given a maximum amount of total funds available, the model can then be applied to distribute these funds over the countermeasures in such a way as to minimize NII. Results for a statistically average U.S. city (Spokane, WA) show that source reduction of surface transformation vehicles is most cost-effective followed by aircraft source reduction. Increasing residential building attenuation becomes cost-effective only at very high levels of total funds available. Moving people away from noise sources has not appeared as a viable alternative in the analyses conducted so far. Further work is needed for the results of the model to be more generally applicable. [Program supported by the Motor Vehicle Manufactures Association.]