WORK has started on a multi-million pound project to upgrade parts of the A1 into a three-lane motorway.

The first stage of the £520m scheme across the north of England - the largest road improvement project of its kind in Britain - is under way in Yorkshire.

Thirty-three miles of the A1 from Darrington in West Yorkshire to Dishforth in North Yorkshire is being upgraded to motorway standard in the first phase at a cost of £245m.

The work involves the construction of 15 miles of motorway between Ferrybridge and Hook Moor and Wetherby and Walshford.

Transport Secretary Alistair Darling said yesterday the project demonstrated the Government's commitment to upgrading a vital transport artery, connecting the North and North-East to the rest of the motorway network.

The road will be built and operated by Road Management Services (RMS).

RMS will be paid by a new system developed by the Highways Agency that partly relies on the company's success in minimising congestion and reducing road accidents.

Highways Agency project manager Alec Briggs said: "RMS will be paid on a sliding scale depending on the speed and volume of traffic using the road.

"This will act as an incentive for them to conduct essential activities, such as maintenance works at off-peak times and attend to incidents quickly."

A contract to upgrade the 24 miles of the A1 north of Dishforth is expected to be awarded next month.