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Title: HEAVY-TRUCK NOISE EMISSION LEVELS ON GRADES IN CALIFORNIA
Accession Number: 00460077
Record Type: Component
Availability: Find a library where document is available Abstract: As part of a federally funded research project to update vehicle noise emission levels, the California Department of Transportation (Caltrans) examined heavy truck noise emission levels on grades in California. Nearly 1,800 noise measurements were taken at 6 locations along Interstate and state freeways with grades ranging from +3 to +7 percent. The six sites were located far enough upgrade to allow heavy trucks to decelerate from free-flowing speeds of 55 to 60 mph to sustained crawl speeds before measurement. The noise data showed no direct grade dependency at any observed speed. This may have been caused by the inverse relationship between grade steepness and truck weight for a given speed. In order to maintain the same crawl speeds, trucks must be carrying lighter loads on steeper grades, and vice versa, possibly resulting in offsetting effects on noise emission levels. Further research into the exact cause is recommended. Speed dependency, however, was significant. A second-degree polynomial equation for noise energy versus log sub 10 speed was found to represent the best curve fit. A combined speed-dependent curve for +3 to +7 percent grades was developed. Observed speed distributions were found to be grade dependent and appeared to agree with those typically found for trucks on grades in California. This information was used to develop "default" reference energy mean emission levels for heavy trucks on grades up to +7 percent in 1-percent increments. For 3 to 5 percent grades, these values are 1.4 to 0.5 dBA higher than those developed by the currently used NCHRP 117 method; above 5 percent grade the default values are 0.2 to 2.1 dBA lower than those of NCHRP 117.
Supplemental Notes: Publication of this paper sponsored by Committee on Transportation-Related Noise and Vibration. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
Monograph Title: Monograph Accession #: 01419462
Authors: Hendriks, Rudolf WPagination: pp 40-51
Publication Date: 1986
Serial: ISBN: 0309040523
Media Type: Print
Features: Figures
(15)
; Maps
(1)
; References
(6)
; Tables
(9)
TRT Terms: Uncontrolled Terms: Geographic Terms: Subject Areas: Data and Information Technology; Highways; Motor Carriers; Operations and Traffic Management; Planning and Forecasting; I72: Traffic and Transport Planning
Files: TRIS, TRB
Created Date: Nov 30 1986 12:00AM
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