Tread Careful

The A421 is a key part of the east-west corridor liking Cambridge and Oxford. It is designated in the Bedfordshire Structure Plan as a strategic growth corridor in need of economic and environmental regeneration. The Highways Agency is investing £200M to transform this gridlocked route by building 13 kilometres of new dual carriageway alongside the existing road. Realignment work is being planned at the same time as dual carriageway construction so a temporary bypass is being built and which will later form part of the local network. Because some of the route runs across a former slurry pit, traditional construction methods were either very expensive or very laborious. The idea of using old tyre bales was mooted. Benefits include lower costs, environmental benefits and the opportunity to source the old tyres locally. The use of tyre bales was successfully piloted in Scotland, for subgrade improvements in areas of peaty ground. Technical details of the construction process on the A421 are described and plans are afoot for TRL will monitor vertical and lateral displacements, as well as pore pressure changes prior to final completion.


  • English

Media Info

  • Pagination: 28-29
  • Serial:
    • Volume: 42
    • Issue Number: 10
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 01146917
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 24 2009 8:29AM