The development of a maintenance-free motorway traffic signal and sign gantry is described. Precast concrete was used for the main portal and aluminium for the facia/traffic signal system. It is estimated that 25 per cent capital cost savings could be achieved when compared to the traditional steel box-type portal. A simple voided reinforced concrete structure is used for the portal beam, portal legs are not voided and are tapered in the plane facing the motorist. The structural requirements of the knee joint are discussed. During construction, the legs are connected into preformed sockets in the in-situ bases before casting the knee joints. The system has been devised to give ample tolerances on site and can be erected over an existing motorway with only a very short full carriageway closure required for beam placement. In this case the two basic aluminium units should be erected prior to lifting together with the l shaped sign supports and prefabricated facia/walkway supports. /TRRL/

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 21-22
  • Serial:
    • Construction
    • Publisher: Reed Construction Data
    • ISSN: 0045-3900

Subject/Index Terms

Filing Info

  • Accession Number: 00195562
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0 11 724 430 9
  • Files: ITRD, TRIS
  • Created Date: Aug 28 1979 12:00AM