A model for estimating operating speeds on combined horizontal and vertical alignments on rural two-lane highways /
The problem of inconsistencies on the geometric design of
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736824061&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The problem of inconsistencies on the geometric design of highways has been linked with an increasing number of accidents on rural two-lane highways. The design-speed concept has been used mainly in the United States to guarantee design consistency of all the geometric features of a highway alignment. Research and experience in other countries indicates that the use of operating-speeds in the design consistency analysis of rural two-lane highways is more effective in detecting inconsistencies. This research investigates and expands the use of operating speeds in the analysis of design consistency. Using speed measurements taken in six states, a series of regression equations were developed to predict the operating speeds of passenger vehicles on different alignment combinations in rural two- lane highways. The regression equations were based on a limited number of sites per alignment combination and they may not reflect the actual speed behavior of similar curves. An attempt was made to modify these equations for trucks and recreational vehicles but the limited data prevented the development of meaningful equations. The regression equations developed in this research were included in the speed-profile model suggested in Federal Highway Administration's report FHWA-RD-94-034. The speed-profile model herein presented intends to detect geometric inconsistencies in most of the alignment combinations. An example of the application of the regression equations in the speed-profile model is provided to illustrate the use of the model. |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | xi, 142 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 108-112. |