Effectiveness of traffic noise barrier on I 471 in Campbell County, Kentucky

Abstract

The objective of this study was to evaluate the effectiveness of a traffic noise barrier on Interstate 471 in Campbell County, Kentucky. Because construction of the barrier coincided with construction on I-471, it was necessary to predict noise levels that would exist if no barrier were present by using the FHWA STAMINA 2.0 computer model. The model results were compared to actual noise level measurements at the barrier site to determine the barrier insertion loss. After calibration of the STAMINA 2.0 model, noise measurements were made at 39 receiver locations during peak and off-peak traffic periods. The noise barrier reduced the noise level at adjacent residences substantially. After barrier construction, 15 homes (14 percent of the total study sample) experienced a peak period L sub eq insertion loss of 10 dBA or more, and another 58 residences (54 percent) were observed to have a peak period insertion loss of 5.0 to 9.9 dBA. Comparison of insertion loss between values predicted by STAMINA 2.0 and actual field measurements was very close. Analyses indicated that insertion loss values predicted by the STAMINA 2.0 model will be achieved by the noise barrier. A survey of community perception of the noise barrier was also performed. Of 103 questionnaires mailed, 66 (64 percent) were returned. Community perception of the barrier was favorable: 64 percent of the respondents generally liked the noise barrier, and 95 percent felt it was effective in reducing traffic noise.