BACKGROUND
The Federal Highway Administration (FHWA) developed the Roadway Construction Noise Model (RCNM) in response to growing public concern and complaints about construction noise. The RCNM is based on the construction noise model developed and utilized at the Central Artery/Tunnel Project in Boston. The data used for the RCNM has since been used as a reference source for construction equipment noise emissions and predictions. The model itself has been used for planning and environmental assessment, construction noise mitigation plans, regulations development, and specification enforcement. RCNM uses simplified assumptions (e.g., equipment usage factors) that limit its flexibility and accuracy additionally, the construction equipment noise database in RCNM provides only broadband Lmax A-weighted levels, the calculation of time-dependent noise metrics is done by estimation, and it neglects the excess attenuation provided by ground effects and air absorption losses.
To ensure compliance with state, local, and project-specific noise restrictions, under the NCHRP 25-49 project, RCNM 2.0 was developed, an improved model for predicting construction noise and the effects of noise reduction efforts. The objective of this research was to develop and validate a noise model to calculate the acoustic environment associated with highway construction equipment and activities, to accumulate a database of noise sources, and to document the appropriate applications of the model.
Note:
Noise data may be accessed through the attached link https://onlinepubs.trb.org/onlinepubs/nchrp/docs/EquipDB.Source.zip.
The Noise Source Database is found in the file EquipDB.Source.zip. Either extract or open the zip file and you will find two folders: EquipDB.Source.Level and EquipDB.Source.Energy. Each folder contains a text file called Equipment.ID.Name.Map.txt that serves as an index and a series of CSV files that contain the Noise Source Database. The CSV files in the folder EquipDB.Source.Level provide the 1/3rd octave band data for each piece of equipment in the Noise Source Database. The CSV files in the folder EquipDB.Source.Energy provide the energy conversion data for each piece of equipment in the Noise Source Database. Use caution when working with these file because the file names in each folder are the same.
