The 'Area 8' MAC covers the strategic road networks crossing Northamptonshire, Bedfordshire, Hertfordshire and Cambridgeshire and the unitary authority regions of Milton Keynes and Luton. The strategic roads in Northamptonshire will migrate to Area 7 in June 2009.
The contract which is due to start in September 2008 will run until September 2013, with the potential for two one year extensions through until 2015.
WSP has a 40% stake in the joint venture, with Carillion holding the remaining 60%
WSP Chief Executive, Chris Cole, said: "We look forward to continuing to work with Carillion to deliver economic, technical and sustainable innovations to support the Highways Agency in achieving its mission of 'Safe roads, Reliable journeys and Informed travellers'. This award in the UK complements our growing international transport and infrastructure activities."