Solid safety barriers as a highway traffic noise reduction strategy

Abstract

Placing solid safety barriers (concrete crash barriers) along a highway, instead of steel guard rail, can help reduce traffic generated noise at nearby sensitive sites. The effectiveness of these barriers on traffic noise levels is dependent on the height of the barrier, the number of traffic lanes, vehicle mix, and the elevation of the receiver relative to the barrier. The effect of solid safety barriers for sites at a variety of distances from a highway has been investigated for both city streets and freeways of various widths using the U.S. Federal Highway Administration Traffic Noise Model (TNM). TNM predicted noise level reductions, attributable to solid safety barriers, were developed for research scenarios in locations with both hard soil and lawn ground types. Results show a readily perceptible and sometimes substantial noise reduction at sites within a few hundred feet of the roadway.