MOTORISTS are being warned of lengthy diversions for six weeks, and farmers and hauliers for 16 weeks, ahead of a £197,000 scheme to bolster a historic bridge over the River Swale.

North Yorkshire County Council said work would start on Monday, March 23 to restore the grade II listed Thornton Bridge, near the junction of the Topcliffe to York and Easingwold to Boroughbridge and Ripon roads.

The authority said the shortest acceptable diversion would be more than 18 miles.

The first phase of works on the 1865 bridge, which features stone arches, will see its parapets painted where the road is 3.6m wide, forcing its closure for six weeks.

During the following ten weeks of work to prepare and paint wrought iron on the underside of the bridge, the road will be reopened, but a vehicle weight restriction of three tonnes will be enforced.

A council spokesman said: "The structure requires maintenance in order to restore the condition of the bridge parapets and main beams, below the bridge, and as such the bridge will be repainted.

"The contractor will be working seven days a week to progress the works as quickly as possible."

The second phase of work planned in the coming year will look to address the amount the bridge moves due to traffic loads.

The authority said the shortest acceptable diversion route would be through Brafferton, Raskelf, Hutton Sessay, Little Hutton, Dalton, Topcliffe and Cundall.

It said the shorter diversion route, through Sessay would not be signed due to the narrow roads and lack of passing places.