Use of Development Date in Noise Barrier Reasonableness Determinations

The current FHWA noise regulation, Procedures for Abatement of Highway Traffic and Construction Noise, 23 CFR 772 (FHWA noise regulation) 1, permits State Highway Agencies (SHAs) to consider the dates when land uses adjacent to the highway were constructed in determining whether noise barriers are reasonable, but only if the SHA conducts a statewide outreach program to provide noise compatible planning strategies in accordance with section 772.17(b) of the regulation. The Tennessee Department of Transportation (TDOT) has received FHWA approval and currently considers development date in the reasonableness process. TDOT considers development date in the determination of the Base Allowance for each impacted area for which a noise barrier is evaluated. The Base Allowance for development that predated the highway is twice as high as the Base Allowance for development that was knowingly constructed adjacent to an existing highway, making development date a critical factor in the reasonableness determination. This paper discusses the requirements of the FHWA noise regulation regarding the consideration of development date, the history of TDOT's noise policy as it relates to development date, TDOT's statewide outreach program, and TDOT's implementation experiences.