Noise model-to-monitor case study

Final report; Sponsored by Ohio Department of Transportation, Office of Statewide Planning & Research ; Project ID number: 109463, Contract or grant no. 33809; "November 2021."; Additional project information provided in email with PDFs: SJN 135972; Includes bibliographical references (pages 39-42 of Final report)Final report (138 pages) -- [Fact sheet] (2 unnumbered pages)The Ohio Department of Transportation (ODOT) noise program includes an inventory of more than 250 miles of noise barriers around the state. Each noise barrier constructed must be analyzed using the FHWA Traffic Noise Model (TNM) software program to determine if the construction of the barrier is justified. This research study was initiated to identify opportunities to improve the accuracy and validity of ODOT's traffic noise analysis and TNM modeling specifications with specific attention made to the modeling of heavy trucks. Over 44 hours of traffic noise data were collected at noise-sensitive areas at a Type II noise wall project being constructed along Interstate 270 in southeast Columbus. A "model-to-monitor" approach was used to analyze the field-measured noise data and compare the measured traffic noise levels with the traffic noise levels predicted using a robust TNM layout developed by the research team. The results of the analysis were consistent with other national research studies on the topic of meteorological effects, modeling residential building structures, and vegetation effects. Consequently, several useful strategies to aid in improving the accuracy of the traffic noise analysis and modeling process were identified. It is recommended that ODOT revise its traffic noise analysis procedures to carry out field studies only under calm (e.g., no wind) conditions. Additionally, ODOT's TNM specifications should be revised to include modeling of residential structures near the freeway as TNM noise barrier objects and that greater attention be paid to roadside vegetation in the modeling process and highway construction proces