How does the length of the noise barrier affect its noise reduction capabilities?
To minimize the potential for a reduction in the noise barrier’s performance, the barrier should extend a minimum of four times the perpendicular distance from the receiver to the barrier along a line drawn between the receiver and the roadway, according to the FHWA. Another way of looking at this is that the angle subtended from the receiver to a barrier end should be at least 80 degrees as measured from the perpendicular line from the receiver to the roadway.
