M6 North Extension, United Kingdom

The M6 is one of the major arterial roads running along the backbone of the UK. However, the M6 at junction 44 reverts to being a dual carriageway (the A74) which is a bottleneck (A74 carries 44,000 vehicles per day) between the motorway system of Scotland connecting with the motorway system of England.

In July 2006 work was started by the Department of Transport to upgrade the A74 between junction 44 to just south of Gretna Green (Guards Mill) where the A74 becomes the M74. In this way there will be a continual motorway connection from London to Glasgow.

Work on the road upgrade and the construction of a new 'A' road at its side for local traffic is expected to be completed by December 2008. The project is costing an estimated £174m and is being funded by the Department of Transport. The project is being overseen by the Highways Agency.

CONTRACT WORK

The extension of the M6 will run from the north of Carlisle (Junction 44) to Guards Mill near Gretna. The current A74 will be replaced but the new road will follow the line of the existing A74.

The new all-purpose route for local and non-motorway traffic will be to the west of the new motorway, running parallel to it and in places it will use existing roads. It will provide access to all nearby villages and properties as slip roads to and from the existing A74 will then be closed.

Improvements also include two new bridges that will be built at Mossband and Metal Bridge. At Mossband a bridge will be built over the West Coast Main Line railway to carry both carriageways of the new motorway and the all-purpose route.

At Metal Bridge a bridge crossing the River Esk alongside the existing A74 bridge will be built to carry the southbound carriageway over the river. In addition, a new, larger and better equipped site for the Vehicle and Operator Services Agency (VOSA) will be built a mile (1.5km) north of its current location.

CONTRACTORS AND CONSTRUCTION

Two of the main contractors for the project are Carillion Construction (Carillion Roads) and their design consultants, Capita Symonds. Carillion are providing a range of services including environmental assessment, management and design, geotechnical engineering, highway design and structural engineering.

The project is progressing according to schedule and in June 2007 engineers moved a new 800t motorway bridge (designed by Grontmij) into place across the river Esk (bridging the Cumberland Gap) using cranes, cables and hydraulics.

The new 17m-wide bridge was reported to have cost £5.2m. The bridge, which was moved in two stages (the first 100m section in May 2007), was finally completed by an 80m section in June. The bridge deck is now being concreted. At the Mossband Viaduct the foundations and walls are complete and 75% of beam placement is complete. The deck concreting here is ongoing.

Sections along the All Purpose Route (APR) between Floriston and Metal Bridge and Mossband to Guards Mill have been surfaced and are being used by local traffic. Work on the remaining areas is progressing. At the new VOSA site the existing land is being levelled to allow construction of the VOSA facility and the APR. This will involve the removal of around 200,000t of soil for the construction of embankments around the site.

HISTORY

The Highways Agency appointed Carillion Construction Limited in February 2003 under the Highways Agency's Early Contractor Involvement (ECI) initiative, to take the scheme forward. This allowed for development and detailed planning of the works to be carried out while the scheme was taken through the statutory procedures including the 2005 public enquiry, which noted a number of objections.

The Secretary of State for Transport passed the project through in 2006 after deliberating over the objections.

SAFETY ISSUES

The M6 Extension is basically a widening scheme that will complete the motorway when it is opened to traffic at the end of 2008.

The scheme will more importantly resolve the safety problems caused by the change from motorway standard at either end of the section and remove the conflicts between local/agricultural traffic and the high speed through traffic and replace the Mossband Viaduct over the West Coast Main Line, which is in very poor condition and was planned for replacement anyway.

In August 2007 the new VMS (variable message system) signage linked to the National Traffic Control Centre was installed on the north west sections of the M6. This will improve safety again and when the M6 extension is completed further signs will be installed.