[Code of Federal Regulations]
[Title 23, Volume 1]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 23CFR772.17]

[Page 395]
 
                           TITLE 23--HIGHWAYS
 
 CHAPTER I--FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
 
PART 772--PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE--Table of Contents
 
Sec. 772.17  Traffic noise prediction.

    (a) Any traffic noise prediction method is approved for use in any 
noise analysis required by this regulation if it generally meets the 
following two conditions:
    (1) The methodology is consistent with the methodology in the FHWA 
Highway Traffic Noise Prediction Model (Report No. FHWA-RD-77-108).*
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    *These documents are available for inspection and copying as 
prescribed in 49 CFR part 7, appendix D.
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    (2) The prediction method uses noise emission levels obtained from 
one of the following:
    (i) National Reference Energy Mean Emission Levels as a Function of 
Speed (appendix A).
    (ii) Determination of reference energy mean emission levels in Sound 
Procedures for Measuring Highway Noise: Final Report, DP-45-1R.*
    (b) In predicting noise levels and assessing noise impacts, traffic 
characteristics which will yield the worst hourly traffic noise impact 
on a regular basis for the design year shall be used.