Noise Model-to-Monitor Case Study

US Transportation Collection2021PDFTech ReportSperry, Benjamin R.Destocki, DevonCubick, Karel L.Rochat, JudyOhio University. Ohio Research Institute for Transportation and the Environment (ORITE)Ohio. Department of Transportation. Office of Statewide Planning and ResearchUnited States. Department of Transportation. Federal Highway AdministrationOhio. Department of Transportation. Office of Statewide Planning and ResearchOhioUnited StatesData analysisData collectionHeavy duty trucksNoise barriersTraffic noiseFHWA/OH-2021-3633809Final reportThe 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 Federal Highway Administration (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\u2019s 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 \u201cmodel- to-monitor\u201d 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\u2019s 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 process.143