A STUDY OF HIGHWAYS WITH A NARROW MEDIAN-CALIFORNIA

THE SAN RAFAEL FREEWAY WAS CONSTRUCTED IN 1939-40 TO ALLEVIATE A SERIOUS BOTTLENECK THAT HAD DEVELOPED IN SAN RAFAEL DUE TO THE INCREASED VOLUME OF THROUGH TRAFFIC USING THE NARROW CITY STREETS WHICH WERE ALREADY TAXED TO CAPACITY BY MEASURED LOCAL TRAFFIC. THE VIADUCT STRUCTURE WAS SELECTED TO CARRY THE FREEWAY THROUGH THE MORE CONGESTED PART OF TOWN, SO AS TO ALLOW A FREE PASSAGE OF LOCAL TRAFFIC UNDER THE VIADUCT ON EXISTING CITY STREETS. A NARROW MEDIAN WAS USED AS A SAFETY PRECAUTION TO MORE EFFECTIVELY SEPARATE THE OPPOSING FAST-MOVING TRAFFIC. THE USE OF A NARROW MEDIAN WAS AN ECONOMICAL EXPEDIENT RESULTING IN A SAVING IN WIDTH OF ROADWAY, VIADUCT STRUCTURE AND RIGHT-OF-WAY. THE FREEWAY HAS DEMONSTRATED ITS ABILITY TO CARRY A LARGE AMOUNT OF THROUGH TRAFFIC AND AT THE SAME TIME PROVIDE SAFE INGRESS AND EGRESS FOR LOCAL TRAFFIC. THE MEDIAN HAS BEEN EFFICIENT IN PREVENTING ACCIDENTS INVOLVING OPPOSING TRAFFIC AS IS EVIDENT BY THE ABSENCE OF ACCIDENTS OF THAT NATURE. AS THERE ARE NO LEFT TURNS PERMITTED AND THEREFORE, NO NEED FOR MEDIAN STORAGE LANES, A WIDER MEDIAN WOULD SEEM TO BE OF NO ADVANTAGE. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/35/35-002.pdf
• Supplemental Notes:
  • No 35, pp 3-18, 10 FIG, 7 PHOT 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
• Authors:
  • Telford, E T
• Publication Date: 1951

Media Info

• Media Type: Print
• Pagination: pp 3-18
• Monograph Title: Highways with a narrow median
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 35
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Freeways; Highway capacity; Highways; Medians; Prevention; Safety; Traffic volume; Viaducts
• Candidate Terms: Highway economics
• Old TRIS Terms: Narrow objects
• Subject Areas: Design; Highways; Safety and Human Factors; Security and Emergencies;

Filing Info

• Accession Number: 00203381
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Apr 21 1994 12:00AM