Gridlock gripped Oxfordshire's roads today as a serious collision involving three lorries on the A34 caused chaos in and around the city.

A queue of traffic snakes into the distance on the northbound A34 at South Hinksey at 8.30am

The A34 was closed between the Pear Tree and Botley interchanges at about 4.30am after the crash. One of the lorry drivers is believed to have life-threatening injuries.

The southbound carriageway, where the accident happened, was expected to remain closed until about 2pm.

The northbound carriageway, which was being used by emergency vehicles to get to the scene, was re- opened at 8.20am.

Long delays were reported on roads in west Oxfordshire, Yarnton, Kidlington and Berinsfield, as drivers tried to find alternative routes.

There were also long tailbacks on the A40 westbound towards Headington, and on the A34 southbound from Weston-on-the-Green.

Problems were compounded by a crash on the A34 southbound, near junction nine of the M40, involving two vans and a car, which spilled diesel fuel on the road at about 10.30am.

There were delays in Oxford when a number of lorries drove along Botley Road, but were forced to turn back at the railway bridge near Oxford station because they were too high to fit underneath.

Mike Thurgood, 59, an employee of Newsquest Oxfordshire, which publishes the Oxford Mail, said: "I saw a lorry that was too high to go under the station bridge at about 5.40am. He was trying to back up, and there was another lorry beside him that was also trying to back up."

A spokesman for the Highways Agency, which manages the A34, said: "We can only reopen the route when it is safe to do so."

She said there had been tailbacks as far as junction nine of the M40, where it joins the A34. However problems had eased by 8am. Signs on the M40 warned drivers of delays ahead.

The chaos unfolded after a 44-tonne articulated lorry travelling south went out of control just north of the Botley interchange and came to rest on its side, blocking the southbound carriageway.

A car transporter collided with the first lorry, trapping the driver in his cab, and causing the car transporter to shed its load of Jaguar cars.

A 20-tonne lorry then collided with the wreckage and ended up on its side.

The driver of the car transporter was taken to John Radcliffe Hospital in a very serious condition.

Sub Officer Pete Whitaker, watch manager at Oxford's Rewley Road fire station, said: "He was seriously injured and trapped in the cab of his lorry.

"The lorry in front had rolled on to its side and he had gone into the wheels."

He said because of the seriousness of the driver's injuries, firefighters worked to cut him free as quickly as possible. Mr Whitaker said traffic jams had made it difficult for firefighters to get to the scene.

The other drivers were taken to hospital with minor injuries and shock.

Police were warning motorists in Oxford to allow extra time for their journeys to work this morning.

One motorist, who travels from Long Hanborough into Oxford, said it took her two hours and 10 minutes. She encountered long delays on the B4044 and at the Swinford toll bridge.

The A44 at Yarnton was also affected by delays.

PEERS Technology College in Littlemore, Oxford, was forced to close until midday and William Fletcher Primary School, in Yarnton, postponed the start of lessons until 10am.

Chris Dark, headteacher at Peers, said it was the first time staff could remember the school ever having to close because of traffic problems in 30 years.

He said: "At 8.15am this morning, we only had about six staff, instead of 70, so we decided to postpone opening until midday.

"In hindsight, we could probably have reopened a bit earlier, but I didn't want to send pupils away twice in one morning.

"We printed off letters for parents explaining the situation and if any youngsters had difficulties going home, they were allowed to stay at school. It's the first time we've ever delayed opening because of traffic."

Shops and businesses in Oxford were struggling to get back to normal today due to the knock-on effects of the traffic chaos.

Many were forced to operate on a skeleton staff while colleagues struggled into work and it was mid-morning before they could trade normally.

Sonia Galib, manager of the Schuh shoe shop, in Magdalen Street, said: "It was very difficult to open on time, as staff had simply not arrived.

"One says she is standing at a bus stop with about 50 other people who have left their cars outside the city. But there's not a lot we can do about it."

Elsewhere in the city, managers at the Clarendon and Westgate centres were reported as being stuck in traffic when the Oxford Mail called them just after 10am. Staff at the Clarendon Centre said there were fewer shoppers than normal, although shops opened on time.

Debbie Daly, a spokesman for Cowley-based Unipart, said: "Some people have taken two and a half hours to get here.

"Fortunately most of our transport goes out on to the M40, so has not been affected."