A Comparative Study of Insertion Loss of Traffic Noise Barriers in Georgia

In this paper, three types of traffic noise barriers, interlocking steel panels, precast concrete panels, and Paragon panel 23-T, were evaluated in terms of insertion loss. Field test was conducted for the noise barriers recently installed as part of the Northwest Express Project in Georgia. The noise insertion loss was measured as noise difference in A-weighted decibels (dBA) immediately before and after the barriers. The insertion loss was then evaluated by correlating with noise barrier types and other influential variables, including the separation distance of barriers from traffic, the level of traffic, wind speed, and pavement types. The results showed that under prevailing conditions represented by other influential variables, all three barrier types achieved an insertion loss in the range of 7.02 dBA to 13.58 dBA, exceeding the noise reduction design goal of 7 dBA as stated in the Georgia Department of Transportation’s noise abatement policy. Among the three, the Paragon panel 23-T barriers effected the highest insertion loss, followed by the precast concrete panel barriers and the interlocking steel panel barriers