TRAFFIC FLOW EXPERIMENTS IN THE QUEENSWAY MERSEY ROAD TUNNEL 2. ANALYSIS OF OBSERVATIONS

THIS IS THE SECOND OF TWO ARTICLES DESCRIBING TRAFFIC FLOW EXPERIMENTS CARRIED OUT IN THE QUEENSWAY MERSEY TUNNEL IN ORDER TO ASSESS THE POTENTIAL INCREASES IN CAPACITY WHICH COULD RESULT FROM THE INTRODUCTION OF FLOW CONTROL SCHEMES. THE DEVELOPMENT OF A DATA LOGGING SYSTEM FOR THE COLLECTION OF SPEED/HEADWAY DATA WAS DESCRIBED IN THE JULY 1973 ISSUE AND THE ANALYSIS OF THESE DATA IS NOW DISCUSSED. THE WORK SHOWS THAT THE STEADY-STATE RELATIONSHIPS CAN BEST BE DESCRIBED BY THE MAY AND KELLER CAR-FOLLOWING MODEL AND AN ALTERNATIVE DERIVATION OF THIS EQUATION USING RATE-OF-CHANGE OF VISUAL ANGLE AS THE STIMULUS IS GIVEN. THE EFFECT OF GRADIENT IS SHOWN TO REDUCE THE DOWNGRADE FREE SPEED OF 38 MILE/H IN THE CENTRE LANES TO 33 MILE/H ON THE UPGRADE, THEREBY PRODUCING A SITUATION IN WHICH INPUT MAY EXCEED BOTTLENECK CAPACITY AND RESULTING IN ONE-MINUTE FLOWS WHICH ARE GENERALLY BELOW THOSE GIVEN BY THE CORRESPONDING STEADY-STATE CURVE. A CONTROL STRATEGY BASED ON LIMITING THE ENTRY RATE TO THE BETTLENECK CAPACITY OF 28 VEH/MIN. IS SHOWN TO HAVE THE POTENTIAL TO INCREASE THROUGHPUT IN THIS LANE BY UP TO 40 PER CENT. (A) SEE ALSO IRRD ABSTRACT NO. 207380

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00410683
• Authors:
  • Heyes, M P
  • Ashworth, R
• Publication Date: 1973-4-9

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 222-5
• Serial:
  • Traffic Engineering & Control
  • Volume: 15 N
  • Issue Number: n/5
  • Publisher: Hemming Group, Limited
  • ISSN: 0041-0683
  • Serial URL: http://www.tecmagazine.com/

Subject/Index Terms

• TRT Terms: Bottlenecks; Equations; Highway capacity; Information processing; Measurement; Traffic flow; Travel patterns; Tunnels; Vehicular tunnels
• Uncontrolled Terms: Traffic patterns
• Old TRIS Terms: Tunnel capacity
• Subject Areas: Bridges and other structures; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226894
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: TRIS
• Created Date: Jul 16 1974 12:00AM