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Barrier wall B2 was modeled to reduce noise impacts to residences along New Ryder Road.
The barrier was modeled at 918 feet in length and was evaluated at 5 fixed heights of 25 feet, 20 feet, 15 feet, 12 feet, and 10 feet.
Feasibility
For all 5 barrier wall height scenarios (25 feet, 20 feet, 15 feet, 12 feet, 10 feet), barrier wall B2 meets the criteria for both acoustic feasibility and engineering feasibility
Since both acoustic and engineering feasibility criteria are met, the evaluation continues for reasonableness
Reasonableness
•Noise Reduction Design Goal
Barrier wall B2 with wall heights of 25’, 20’, 15’, and 12’ meets the noise reduction design goal; therefore, evaluation continues for cost effectiveness
Barrier wall B2 with 10’ wall height does not meet the noise reduction design goal; therefore, the evaluation stops and the barrier wall of 10’ wall height is considered not reasonable to construct.
Cost-effectiveness – cost estimates were prepared for the 4 barrier wall height scenarios that meet the noise reduction design goal. The cost estimates were based on a $35/square foot cost as prescribed by SCDOT’s Noise Abatement Policy.
Barrier wall B2 with wall heights of 25’, 20’, 15’ and 12’ all exceed the allowable $30,000 cost per benefitted receptor; therefore, the evaluation stops and the barrier walls are considered not reasonable to construct.
