TRAFFIC LIGHTS COULD SAVE SEVERN BRIDGE

The rapid increase in lorry weight has led to an increase in loading standards on bridges. The cables of the Severn Bridge are strong enough to meet the new standard but the rest of the structure will need strengthening. It is suggested that traffic lights at either end of the bridge could make the proposed 33 m strengthening plan unnecessary. At present, the loading does not exceed 300 tonnes for 98 per cent of the time, and very rarely exceeds 1200 tonnes on the central span which has a design load of 2000 tonnes. Current plans are to increase the strength of the bridge to meet a new design standard of 5000 tonnes. An examination by consultants suggests that the bridge could collapse if it sustained a load along a 200 m section of the main span equivalent to the weight of 18 38-tonne lorries. This condition could be easily prevented by traffic signals controlled by a micro computer linked to axle weight sensors. An alternative scheme would be to set up toll booths on the approaches to the bridge in both directions to limit the number of heavy lorries on the bridge at any one time. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/02624079
• Corporate Authors:

  IPC Magazine Limited

  King's Reach Tower, Stamford Street
  London SE1 9LS,   England 
• Authors:
  • HAMER, M
• Publication Date: 1984-2

Media Info

• Features: Photos;
• Pagination: p. 6
• Serial:
  • NEW SCIENTIST
  • Volume: 101
  • Issue Number: 1397
  • Publisher: REED BUSINESS INFORMATION LTD
  • ISSN: 0262-4079

Subject/Index Terms

• TRT Terms: Axle load force; Bridges; Design; Heavy vehicles; Highway bridges; Numbers; Traffic control; Traffic loads; Traffic signals; Trucks; Ultimate load design; Vehicle detectors; Weight
• Uncontrolled Terms: Increase
• Geographic Terms: United Kingdom
• Old TRIS Terms: Limits
• ITRD Terms: 3067: Axle load; 3455: Bridge; 9011: Design (overall design); 9032: Increase; 6452: Limit; 1236: Lorry; 6432: Number; 654: Traffic control; 565: Traffic signal; 8119: United Kingdom; 5485: Weight
• Subject Areas: Bridges and other structures; Design; Freight Transportation; Highways; Motor Carriers; Operations and Traffic Management; I73: Traffic Control;

Filing Info

• Accession Number: 00391217
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jan 30 1985 12:00AM