WORK on a £60,000 warning system to stop lorries overturning on a north Oxfordshire roundabout was starting today.

The new signs, activated by sensors in the road, aim to encourage lorries to slow down between junction 10 of the M40 and the A43 roundabout at Ardley, near Bicester.

The work, to take place off-peak and overnight, is due to be completed by next Wednesday.

The northbound exit slip road will be shut tonight between 9.30pm and 5.30am.

Traffic wishing to leave the motorway at junction 10 will be diverted to junction 11 at Banbury to join the southbound carriageway back to junction 10.

Extra cones will be on the slip road between 9.30am and 3.30pm, and there will also be overnight lane closures between 9.30pm and 5.30am for the duration of the works.

A Highways Agency spokesman said seven lorries weighing more than 7.5 tonnes had overturned at the junction since 2002.

Highways Agency route manager Bob Gale said: "The new signs will encourage HGV drivers to slow down to cut the risk of overturning accidents on the approach to the A43 Ardley roundabout.

"The signs should help give adequate warning about the risk and help reduce these accidents.

"The work will take place overnight and off-peak when traffic flows are lower."

Ardley parish councillor Colin McGarry said he welcomed the work because the roundabout was known for overturned lorries.

He said: "It is a problem. The articulated lorries go so fast approaching the roundabout, they just can't manage them - particularly not if they have a top-heavy load. It causes chaos."