Grontmij carried out the detailed design of the structures which includes two large bridges; the replacement of a viaduct crossing the West Coast Main Line and a bridge over the estuary of the River Esk. Both structures have brought about a unique set of challenges for the team.

The estuary is environmentally sensitive and the new viaduct crosses the West Coast Mainline, which is one of the busiest railway lines in the UK. After considering many options, the solution for the River Esk was to launch the steelwork for the bridge into position, whilst a wide single span integral bridge using prestressed precast beams was chosen to cross the West Coast Mainline.

This dual carriageway section of trunk road has several minor road junctions and therefore mixes relatively low-speed local traffic with high-speed trunk road traffic.

It has a poor accident record and causes driver frustration, resulting from heavy goods vehicles using the outside lane of each carriageway. The upgrade of this section to motorway standard would bring the following benefits to road users:

• a reduction in the number of accidents on the route;
• the provision of more carriageway space for emergency services attending accidents;
• the provision of more carriageway space to enable traffic flows to be maintained following an accident;
• a reduction in driver frustration;
• an improvement in accessibility for users; and
• the provision of more predictable journey times.

Facts

• Client: Highways Agency
• Start date: July 2006
• End date: December 2008