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Title: WEIGHT-SPECIFIC HIGHWAY SIGN EFFECTS ON HEAVY TRUCKS
Accession Number: 00467852
Record Type: Component
Availability: Find a library where document is available Abstract: The objective of this study was to test the field effectiveness of the Grade Severity Rating System (GSRS), via application of weight-specific signs to control truck speeds on downgrades. Before-after sign effects were evaluated in terms of speed differences and incidences of smoking brakes for trucks in specific weight categories. A five-state (California, Colordo, Idaho, Oregon, and West Virginia) sample of study sites included grades of varying severity. The study design included a determination of novelty effect as well as concurrent before-observations at selected control sites (i.e., no weight-specific sign present). In addition, the feasibility of state highway agencies conducting an accident study to assess GSRS safety impact was examined. Weight-specific signing (WSS) was determined to elicit a favorable before-after effect at high-severity sites. Three truck behavioral measures provided the basis for this result: mean truck speed, percentage of trucks exceeding posted WSS speeds, and incidences of smoking brakes. Before-after reductions in mean speed were observed at two out of three high-grade-severity locations following installation of the WSS. Substantiating evidence that the WSS was responsible for the speed reduction evolved from (a) corresponding speed increases at one matched control site and (b) the absence of speed changes for trucks weighing less than 70,000 lb (31.8 Mg) at the other site. Percentages of trucks exceeding WSS-posted speeds were reduced for 70,000 to 80,000 lb (31.8 to 36.3 Mg) trucks at one site and for 60,000 to 70,000 (27.2 to 31.8 Mg) trucks at the other. The proportion of trucks characterized by smoking brakes was reduced at the single high-severity site where this measure was observed. Because GSRS represents the state-of-the-art, its application was viewed to improve states' liability positions. Weight-specific signing was recommended for use at high-grade-severity locations.
Supplemental Notes: Publication of this paper sponsored by Committee on Traffic Control Devices.
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 #: 01418073
Authors: Hanscom, Fred RPagination: pp 31-36
Publication Date: 1987
Serial: ISBN: 0309044669
Media Type: Print
Features: Figures
(3)
; References
(3)
; Tables
(2)
TRT Terms: Uncontrolled Terms: Old TRIS Terms: Subject Areas: Highways; Motor Carriers; Operations and Traffic Management; I73: Traffic Control
Files: TRIS, TRB, ATRI
Created Date: Mar 31 1988 12:00AM
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