Carillion Construction was appointed by the Highways Agency in February 2003 under an initiative to secure early involvment from contractors. Highways and railway engineers worked together with the Highways Agency's contractors to develop innovative techniques to construct the viaduct while safely keeping trains running.

Among the key features was the use of moving gantry systems to allow construction of the two 160m-long bridge abutment walls, which were 6m high and 1m thick.

Southbound traffic will also be allowed to use the new viaduct within the next few weeks. The 40-year-old existing viaduct will be demolished once the motorway opens to traffic later this year.