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So how do we determine the existing and future noise levels?
Noise levels in an area of interest are determined using a computer-based software created by the Federal Highway Administration called Traffic Noise Model, or TNM, version 2.5 (TNM 2.5). The SCDOT noise policy requires the use of TNM 2.5 for analysis of highway traffic noise.
The images to the right show what a typical noise model may look like in the TNM 2.5 software.
