Defined as unwanted or excessive sound, noise can be caused by a variety of sources related to expanded infrastructure that supports modern society. As mobility increases, transportation, in particular, can be a key source of noise across modes, from airports to rail to new roads.
Studies have shown that some of the most pervasive sources of noise in our environment are those associated with transportation. Residences and businesses often are faced with increased highway traffic noise, both from newly constructed highways and from highways that are already in place.
The National Environmental Policy Act (NEPA) of 1969 provided broad authority and responsibility for evaluating and mitigating adverse environmental effects including highway traffic noise. NEPA directed the Federal government to use all practical means and measures to promote the general welfare and foster a healthy environment.
Public concern about noise led to federal legislation in 1970 that authorized the use of federal aid highway funds for measures to abate and control highway traffic noise. The Federal Aid Highway Act of 1970 (23 USC 109(h)) mandated that the Federal Highway Administration (FHWA) develop noise standards for mitigating highway traffic noise. The law required promulgation of traffic noise-level criteria for various land use activities. The law further provided that FHWA not approve the plans and specifications for a federally aided highway project unless the project included adequate noise abatement measures to comply with the standards.
The following sections provides an overview of transportation noise issues.