A MAJOR project to tackle one of Oxfordshire’s most notorious traffic blackspots begins this week — and the roadworks are expected to stretch on until Christmas.

Motorists will be bracing themselves for long tailbacks at the M40/A34 interchange, where narrow lanes, 40mph speed restrictions and temporary overnight lane closures will be imposed for the next five months.

People living near junction nine have said they fear the work will increase rat-running through nearby villages, as frustrated drivers seek to bypass potential hold-ups.

The £4m first phase of planned upgrades to the M40 junction nine will see the southbound motorway exit and the turn from the roundabout on to the A34 both widened to three lanes.

But a planned £6.5m second phase — to improve the northbound approach to the junction on the A34 and to widen the A41 between the roundabout and Bicester — has been put on hold because of funding concerns.

The agency has admitted road capacity would be reduced during the roadworks, but said it would do all it could to minimise disruption.

The first lane closures will happen tomorrow and Saturday night, from 10pm until 5am.

The northbound M40 exit slip will be closed and diversion routes will be put in place.

Highways Agency spokesman James Wright said that, once complete, the work would increase capacity for southbound traffic and improve vehicle flow across the junction.

A decision on the planned second phase of work has been put on hold until the Highway Agency’s budget settlement is announced in the autumn.

Mr Wright said: “We have plans for phase two and its part of the improvements we want to make.

“When we get future years’ budget allocation, after the Government’s autumn spending review, we will look at what we have in terms of funds and what we can do.

“It is difficult to be more detailed than that at this time.”

He added: “Phase one stands on its own and increases southbound capacity from the M40 on to the A34. It will reduce traffic queuing on the M40, and queues on the live lane of a motorway are a safety issue.”

Mr Wright said there was “no ideal time” to carry out roadworks and that sliproads would only be closed overnight.

He added that restrictions would, if possible, be lifted over August Bank Holiday weekend.

The agency hopes the work will ease traffic problems on local roads and admits many drivers avoid the interchange at present because of delays.

Mr Wright said: “We believe there is a lot of surplus demand in the area — people who would use the junction but rat-run because they believe it’s congested. This work may draw them back to the main route.”

Julian Cordy, chairman of Wendlebury Parish Council, said he feared traffic through the village would increase during the work.

He said: “There will be ‘roadworks ahead’ signs on the A41 and A34 and we fear people will see these and then think ‘I’ll nip through Wendlebury’.”

“We have asked for a ‘no access through the village’ sign, but we have had no response.”

But he added: “We are supportive of the overall aims of the work, particularly if they get funding for phase two.”