RSG Authors National Cooperative Highway Research Program (NCHRP) Report on How Sound Barriers Reflect Noise

Noise barriers do not just block noise, but can also generally change the way noise is experienced around them. To further explore this issue, the Transportation Research Board (TRB)’s National Cooperative Highway Research Program (NCHRP) recently published the RSG-coauthored report Field Evaluation of Reflected Noise from a Single Noise Barrier, which analyzes the characteristics of sound reflected from a noise barrier to the opposite side of a highway. Residents living opposite newly added single noise barriers sometimes complain about increased traffic noise. Currently available analytical tools are limited in their ability to evaluate this reflected noise and some of the subtle changes in the quality of sound that can occur when it is reflected. Therefore, it is a challenge to determine conclusively if complaints about reflected noise are the result of actual or perceived changes in noise characteristics, and to identify locations where absorptive surface treatments could be beneficial.

The study compares reflected noise from sound barriers with different surfaces and examines both the levels, frequencies, and quality of reflected noise to better understand how it is experienced by communities. The report is accompanied by several appendices, a tool, and a guide. Learn more and check them out at: http://www.trb.org/NCHRP/Blurbs/178305.aspx