Bidston Moss Viaduct is a 730m-long box girder bridge which carries the M53 motorway over a roundabout and railway.

The scheme will involve major strengthening work to the viaduct, which opened in 1970 and is the main route into the Kingsway Tunnel under the River Mersey. Design work will start this month and last for 15 months. Construction will start in summer 2010.