ELEMENTS OF MEDIAN DESIGN IN RELATION TO ACCIDENT OCCURRENCE
THE PURPOSE OF THIS STUDY WAS TO COMPARE THE ACCIDENT HISTORIES OF DIFFERENT MEDIAN TYPES AND TO PROVIDE VERIFICATION OF GENERALLY RECOMMENDED MEDIAN WIDTHS AND SLOPES. A MAJOR LIMITATION OF THE ANALYSES WAS THE SMALL NUMBER OF POSSIBLE COMBINATIONS OF MEDIAN WIDTH AND CROSS SLOPE AVAILABLE FOR STUDY. THE ANALYSES REPORTED PROVIDED EVIDENCE FROM ACCIDENT HISTORIES TO SUPPORT THE GENERAL ASSUMPTION THAT WIDER MEDIANS ARE SAFER MEDIANS. IT WAS INDICATED THAT MEDIANS SHOULD BE A MINIMUM OF 30 TO 40 FT WIDE FOR HIGH-SPEED FACILITIES AND THAT FLAT SLOPES SHOULD BE PROVIDED; 4:1 SLOPES ARE INADEQUATE FOR MEDIANS LESS THAN 60 FT WIDE. THERE WAS AN INDICATION THAT 6:1 OR FLATTER SLOPES SHOULD BE USED. RAISED MEDIANS PROVIDED AN UNSUITABLE VEHICLE RECOVERY AREA ON RURAL HIGHWAYS AND WERE ALSO UNDESIRABLE FROM THE STANDPOINT OF ROADWAY SURFACE DRAINAGE. THE IRREGULAR INTERSTATE HIGHWAY MEDIANS THAT RESULT FROM INDEPENDENT ROADWAY ALIGNMENT SHOULD BE USED ONLY WITH ADEQUATE CLEAR ZONES IN THE MEDIAN. SHOULDERS 12 FT WIDE SHOULD BE PROVIDED WHERE GUARDRAIL IS TO BE USED.
- Record URL:
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309021626
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Supplemental Notes:
- Sponsored by Commitee on Operational Effects of Geometrics. 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.
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Authors:
- Garner, Gordon R
- Deen, Robert C
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Conference:
- 52nd Annual Meeting of the Highway Research Board
- Location: Washington District of Columbia, United States
- Date: 1973-1-22 to 1973-1-26
- Publication Date: 1973
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: pp 1-11
- Monograph Title: Relations between geometric design and operations
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Serial:
- Highway Research Record
- Issue Number: 432
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Crashes; Design; Medians; Slopes; Width
- Subject Areas: Design; Highways; Operations and Traffic Management; Safety and Human Factors;
Filing Info
- Accession Number: 00226765
- Record Type: Publication
- ISBN: 0309021626
- Files: TRIS, TRB
- Created Date: Dec 22 1973 12:00AM