TRAFFIC CONTROL SYSTEM MAKES REVERSE TUNNEL PRACTICABLE

THE CALDECOTT TUNNEL CONNECTS SAN FRANSICO AND CONTRA COSTA COUNTY. BUILT IN 1937, IT CONSISTS OF TWO PARALLEL TWO-LANE, ONE-WAY BORES. AS THE COMMUTER TRAFFIC HAS INCREASED, IT HAS BECOME A BOTTLENECK. INSTEAD OF BUILDING A SECOND TUNNEL THE SAME SIZE, A TWO-LANE, REVERSIBLE TUNNEL HAS BEEN BUILT. A SYSTEM OF MOVABLE, FLEXIBLE BARRIERS AND CHANGEABLE SIGNS HAS BEEN DEVELOPED TO CONTROL THE TRAFFIC DURING THE RUSH HOURS. POSITIVE BARRIERS ARE ALSO USED TO INSURE THAT VEHICLES ARE PREVENTED ACCESS TO THE LANES OF OPPOSING TRAFFIC. THE TRAFFIC IS CONSTANTLY MONITORED BY A CLOSED TELEVISION CIRCUIT. ESSENTIAL INFORMATION IS BROADCAST OVER THE NORMAL BROADCAST BANDS AND CAN BE PICKED UP BY THE DRIVERS ON THEIR CAR RADIOS. THE BARRIERS AND THE SIGNS ARE CONTROLLED FROM THE SURVEILLANCE ROOM. THE BARRIERS ARE RAISED AND LOWERED BY ELECTRICALLY OPERATED DOUBLE-ACTING AIR CYLINDERS. /AUTHOR/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/1606878
• Supplemental Notes:
  • Vol 97, No 3, PP 102-105
• Authors:
  • Waight, V H
• Publication Date: 1966-9

Media Info

• Serial:
  • Public Works
  • Publisher: Hanley Wood
  • ISSN: 0033-3840
  • Serial URL: http://www.pwmag.com

Subject/Index Terms

• TRT Terms: Barriers (Roads); Closed circuit television; Commuters; Flexibility; Monitoring; Reversible traffic lanes; Traffic control; Traffic control devices; Traffic signs; Tunnels
• Uncontrolled Terms: Barriers
• Old TRIS Terms: Traffic control systems
• Subject Areas: Bridges and other structures; Highways; Operations and Traffic Management; Passenger Transportation;

Filing Info

• Accession Number: 00225127
• Record Type: Publication
• Files: TRIS
• Created Date: May 25 1994 12:00AM