INSTRUMENTS FOR ROAD TRANSPORTATION

TUNNEL POLICING IS ONE OF THE AREAS WHERE NEW INSTRUMENTATION MAKES IT POSSIBLE TO DO A BETTER JOB. VEHICLE DETECTORS AND ALARM CIRCIUTS ARE USED TO ENABLE CONTINUOUS TRAFFIC OPERATIONS IN THE HOLLAND AND LINCOLN TUNNELS. CLOSED CIRCUIT TELEVISION IS USED TO PERMIT POLICE AT REMOTE LOCATIONS TO RAPIDLY INSPECT THE ENTIRE TUNNEL, AND SMALL PORTABLE TWO-WAY RADIOS ARE USED FOR INSTANTANEOUS VOICE CONTACT AMONG ALL POLICE CONCERNED WITH RESPONDING TO A DISABLED VEHICLE. A NEW CATWALK TRANSPORTATION SYSTEM CAPABLE OF CARRYING POLICE AT FORTY MILES PER HOUR ALONG THE NARROW CATWALK TO ANY POINT IN THE TUNNEL WHERE THEY ARE NEEDED IS USED. REMOTELY OPERATED TRAFFIC CONTROL DEVICES WILL ASSIST IN HANDLING TRAFFIC DURING EMERGENCIES. A SERIES OF VEHICLE DETECTORS USE PHOTOCELLS LOCATED IN THE FRESH AIR DUCT BELOW THE ROADWAY. A TWO INCH DIAMETER HOLE DRILLED AT AN ANGLE THROUGH THE EIGHTEEN INCH-THICK ROADWAY SLAB PROVIDES A LINE OF SIGHT BETWEEN THE FLOURESCENT TUBES WHICH ILLUMINATE THE TUNNEL ROADWAY, AND THE PHOTOCELL. WHEN A VEHICLE PASSES ON THE LANE ABOVE THE PHOTOCELL, THE PATH OF LIGHT RADIATED FROM THE FLOURESCENT TUBE IS BLOCKED BY THE VEHICLE CAUSING A SHARP RISE IN THE ELECTRICAL RESISTANCE OF THE PHOTOCELL. INFORMATION FROM THE VEHICLE DETECTORS, THE TV SURVEILLANCE SYSTEM IS DISPLAYED AT A CENTRAL CONSOLE. ALL INFORMATION IS ORIENTED IN PARALLEL WITH ACTUAL TRAFFIC FLOW THROUGH THE TUNNEL, WITH TRAFFIC ENTERING ON THE RIGHT AND EXITING ON THE LEFT. AN AUTOMATIC CONTROL DEVICE IS USED TO ALLOW FEWER VEHICLES TO ENTER THE TUNNEL IN ONE MINUTE THAN IT COUNTS PASSING THROUGH THE TUNNEL AND OUT OF THE BOTTLE NECK IN THE MINUTE BEFORE. THE RESTRICTION CONTINUES UNTIL THE CONTROL DEVICE AUTOMATICALLY SENSES TRAFFIC IS MOVING THROUGH THE UPGRADE AT SPEEDS ABOVE 20- 5 MILES PER HOUR. THE RESTRICTION ON THE RATE OF ENTERING TRAFFIC IS THEN RAISED UNTIL FULL MOVING TRAFFIC IS SENSED AGAIN. TRAFFIC DENSITIES ARE MEASURED BY COMPUTER TO ASSIST IN TRAFFIC CONTROL. IT IS FELT THAT MONITORING THE RELATIONS AMONG CAPACITY, DEMAND, AND DELAYS CAN INCREASE TRAFFIC PRODUCTION.

• Supplemental Notes:
  • Rpt Tbr-2-68A 21 PP, 20 FIG, 5 REF
• Corporate Authors:

  Port Authority of New York and New Jersey

  225 Park Avenue South, 18th Floor
  New York, NY  United States  10003-1604
• Authors:
  • Foote, R S
• Publication Date: 1968-3

Subject/Index Terms

• TRT Terms: Closed circuit television; Highway capacity; Highway operations; Information processing; Photocells; Traffic; Traffic delays; Traffic density; Traffic signal control systems; Traffic surveillance; Vehicle detectors; Vehicular tunnels
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00225765
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 29 1970 12:00AM