Roadway construction noise model progression and integration with federal highway administration's traffic noise model

In 2006, the Federal Highway Administration (FHWA) published the Roadway Construction Noise Model (RCNM 1.0) to predict noise levels from construction activities. RCNM 1.0 included basic acoustical data for a variety of construction equipment. In 2018, RCNM 2.0 was developed using a similar user interface to FHWA's Traffic Noise Model (TNM) version 3.0. RCNM 2.0 improved prediction of construction noise propagation and mitigation. RCNM 2.0 also expanded the source database and allowed users to analyze the project site conditions using mapping. TNM 3.2 includes integration of the TNM 3.1 software structure with RCNM 2.0. Equipment source data in the RCNM database were calibrated to account for the excess attenuation from each new source height. The RCNM database consists of moving and stationary equipment sources, each with spectra for two-four cardinal directions relative to the equipment, which may not always operate constantly throughout the day. Modeling these novel source features in TNM required new logic to handle stationary point sources, partially inactive sources, and source directionality. The goal of TNM 3.2 was for analysts to combine roadway and construction noise analyses within one file. Doing so required changes to the TNM object intersection rules, as well as all aspects of the user interface including map displays, input commands, and output data tables.