Noise modeling of short safety barriers in FHWA's updated Traffic Noise Model (TNM) version 3.1

Solid safety barriers are commonly constructed along highways. These barriers improve highway safety by preventing collisions and providing separation from slopes or adjacent hazards such as deep water. For elevated and at-grade roadways, shorter barriers have also been shown to noticeably reduce traffic noise. In prior research, modeling methods were developed and evaluated for their ability to accurately calculate the performance of short barriers in reducing traffic noise at the wayside. The modeling results were compared to available field data and to the results of FHWA's Traffic Noise Model version 2.5 (TNM). This paper extends the prior research to compare the results to the newest FHWA TNM version, 3.1.