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Title: SELECTION OF HIGHWAY DESIGN PARAMETERS IN THE PRESENCE OF UNCERTAINTY
Accession Number: 00714937
Record Type: Component
Availability: Find a library where document is available Abstract: AASHTO guidelines on highway design have drawn criticism for their inability to deal with the uncertainty of traffic operations, costs, and physical constraints. Some analysts believe that in light of changing economic and socio-environmental values, new procedures are needed to better address uncertainties and to justify engineering decisions. An analytical model that could be used to determine the optimal design curvature for horizontal curves on two-lane highways is presented. The optimal curvature results in the minimum total cost, defined as the sum of construction, maintenance, and expected user costs. The expected user cost is the sum of expected accident, travel time, and vehicle operating costs. It is shown that: (a) optimal design curvature is highly sensitive to the skewness of the probability distribution of the required curvature; (b) when the mean operating speed is high, optimal design curvature does not change significantly with the changes of standard deviation of speeds compared with the low mean operating speed; and (c) when the mean operating speed is low, the polynomial model best represents the relationship between optimal design curvature and the standard deviation of the operating speeds. When the mean operating speed is high, the linear model best represents the relationship between optimal design curvature and the standard deviation of the operating speeds. The application of the model and sensitivity of the optimum to model parameters are illustrated using numerical examples.
Supplemental Notes: This paper appears in Transportation Research Record No. 1497, Artificial Intelligence and Geographical Information. 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 #: 01399824
Language: English
Authors: Islam, M NazrulSeneviratne, P NPagination: p. 1-9
Publication Date: 1995
Serial: ISBN: 0309061636
Features: Figures
(6)
; References
(22)
; Tables
(2)
TRT Terms: Uncontrolled Terms: Old TRIS Terms: Subject Areas: Design; Highways; I20: Design and Planning of Transport Infrastructure
Files: TRIS, TRB
Created Date: Dec 20 1995 12:00AM
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