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Memorandum |
| U.S. Department of Transportation Federal Highway Administration |
| Subject: | INFORMATION: Highway Traffic Noise - FHWA TNM Version 2.5 Look-Up Program |
Date: | December 16, 2004 |
| From: | James M. Shrouds Director, Office of Natural and Human Environment |
Reply to: | HEPN-20 |
| To: | Division Administrators Federal Lands Highway Division Engineers |
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The Federal Highway Administration released Version 2.5 of the FHWA Traffic Noise Model (FHWA TNM) on April 14, 2004. Since Version 2.5 contains changes in the acoustical calculations of the model, FHWA, with the continued assistance of the Volpe National Transportation Systems Center, has developed FHWA TNM Version 2.5 Look-Up Tables to serve as a database for a new Windows-based program entitled FHWA TNM Version 2.5 Look-Up. This program provides highway traffic noise analysts with a screening tool to be used in simple applications of the FHWA TNM. The previously distributed report FHWA Traffic Noise Model Look-Up Tables and its accompanying DOS program TNMLOOK are superseded.
The FHWA TNM Version 2.5 Look-Up Tables provide a reference of pre-calculated FHWA TNM results for simple highway geometries. The calculations are for an infinitely long, straight roadway over flat ground, with a receiver set at a height of 1.5 m above the ground. If desired, an infinitely long straight barrier may also be included in the calculations.
Specifically, the tables contain results for the following parameters:
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Five vehicle types (automobiles, medium trucks, heavy trucks, buses, and motorcycles) at speeds of 0 to 130 kilometers per hour (km/h) in 10 km/h increments;
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Sound level propagation over acoustically hard or soft terrain;
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A single wall barrier (if desired) at a height of between 2 and 10 m, located at a distance of either 10 or 30 m from the centerline of the roadway; and
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Receivers at distances from 10 to 300 m in 10 m increments from the centerline of the roadway.
This program uses the FHWA TNM Version 2.5 Look-Up Tables to determine sound levels associated with a particular geometry. This program, which should be useful to all individuals involved with the analysis of highway traffic noise, may be downloaded (without restriction) at http://www.thewalljournal.com/a1f04/tnm. All registered users of the FHWA TNM, including State departments of transportation, will receive a copy of this memorandum.
Questions concerning FHWA TNM Version 2.5 Look-Up should be directed to Mark Ferroni (Mark.Ferroni@fhwa.dot.gov) at (202) 366-3233 or Chris Corbisier (Chris.Corbisier@fhwa.dot.gov) at (202) 366-1473.
Attachment
cc: Directors of Field Services
