WORK to strengthen four bridges on major routes through the region is to be carried out at a cost of £2.4 m.

The Highways Agency has announced that the improvement scheme will begin in County Durham on Monday.

The four bridges are Barton North, Barton South and Clow Beck on the A1(M), and the Blackwell Spur Bridge on the A1(M)/A66 interchange.

The two Barton bridges will have parapets replaced, while the bridge deck on the Blackwell Spur will be extended.

Blackwell Spur will also have substantial concrete repair work carried out, as well as repainting and parapet replacement. Clow Beck bridge will have repairs to the pier carried out.

Project manager Andrew Jennings said the safety work would also reduce future maintenance needs, adding: "Some of the work on Clow Beck bridge, for example, is to repair damage which was caused to the structure by a vehicle hitting the bridge pier.

"By making some modifications to the bridges, the impact of future maintenance work can be reduced."

A contraflow system, together with a 50mph speed limit, will be in force during the work.