Council and highways bosses insisted last night they had done all they could to deal with the sudden cold snap.

Gritting trucks drove out ahead of schedule as motorists were caught off guard by the freezing conditions on Tuesday night and Wednesday morning.

Drivers complained of icy roads, but both Oxfordshire County Council and the Highways Agency stressed key routes had been treated — even though the winter gritting programme was not set to start until Saturday.

Ian Hudspeth, the council's cabinet member for transport, said it was the first time snow had fallen in October for 70 years — with up to two inches falling in the south of the county.

Commuters were hardest hit by the weather as the M40 ground to a halt and many motorist complained of slippery conditions on country roads.

The motorway between junctions six and four was closed for most of the day yesterday following a collision between two lorries. A 49-year-old truck driver died in the accident. The man was not from the UK.

Diversion routes on the A40 experienced heavy traffic. The Met Office said temperatures dropped to -5.4C in parts of the county on Tuesday night.

Mr Hudspeth said: "We had been in contact with the Met Office throughout the day on Tuesday and were able to get our teams ready.

"They were operating from 8pm until 5am and did a fantastic job covering the network.

"Our programme first dealt with the A roads and the major roads. Then we turned to roads linking in with the major towns and villages and worked through the night until everything was completed."

He added: "We did everything that we could do."

The Highways Agency said gritting was done along the M40 on Tuesday evening and again in the early hours of Wednesday.

Tailbacks from the M40 collision stretched back 10 miles from junction six at Lewknor to junction eight at Tiddington. One of the lorries in the collision was carrying a shipment of lard, which spread over an area the size of a football pitch.

A police spokesman said weather conditions were not being ruled out as a possible cause of the collision.

Both carriageways of the M40 were expected to be opened by 6pm yesterday. There were reports of drivers sitting in queues on the M40 for more than three hours.

Dan Stone, of Howard Street, Oxford, said: "I heard about the accident first thing so decided to travel between Oxford and High Wycombe cross country. It was a nightmare. Even if there hadn’t been so much traffic, I wouldn’t have been able to go faster than 20mph as it was like an ice rink."

 Rail passengers were stranded for 50 minutes during yesterday's morning rush-hour after a points failure stranded a train at Wolvercot junction, near Oxford.

STAY PREPARED THE Met Office said last night the coldest weather was behind us after temperatures dropped to lows of -5.4C on Tuesday night and into Wednesday morning.

Over the coming days Oxfordshire's weather will see winds coming in from south, bringing more rain.

A Met Office spokesman said: "While this will feel bitterly cold, the temperatures should raise by a few degrees. It is going to be pretty miserable over the next few days and into the weekend, but it will be less cold."