Download or read book Parallel Barrier Effectiveness Under Free-flowing Traffic Conditions written by Gregg G. Fleming and published by . This book was released on 1992 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the results of a measurement study performed at a highway noise barrier site located along Interstate 495 in Montgomery County, Maryland. The objective of the study was to measure the degradation in acoustic performance of a highway noise barrier due to the close proximity of a parallel barrier on the opposite side of the roadway. The test site selected for measurements consisted of a contiguous arrangement of two parallel reflective noise barriers followed by a single noise barrier. Five-minute, energy-averaged, A-weighted noise levels were computed from data measured simultaneously at identical heights and offset positions behind the single and parallel barrier arrangements. A comparison of the measured and predicted results is presented.