UPDATE: M40 reopens 14 hours after horror smash

Emergency services are dealing with a serious crash on the M40 amid reports a car towing a caravan has travelled the wrong way down the carriageway and smashed into two cars. 

The crash is believed to have happened on the northbound carriageway between junction 6 and 7, but both sides of the M40 were blocked off. 

All emergency services are at the scene and eyewitnesses say at least 10 emergency vehicles have raced to the scene past drivers stranded in the queues. 

West Oxfordshire District councillor Colin Dingwall told the BFP's sister paper, Oxford Mail, the vehicle pulling a caravan was travelling "about 60 miles an hour" between junction 7 and 6 at about 4.05pm.

The car and caravan was said to be travelling London-bound, but on the northbound carriageway.

Mr Dingwall said he and the other drivers around him "managed to pull out of the lane" to avoid it.

He added: "I've seen a lot of things in my 50 years on the road, but I've never seen a caravan coming the wrong way up the M40.

“Luckily I and the cars near me managed to pull into the middle lane and get out of the way.

“He must have been going about 60mph. It was a car with foreign plates pulling a caravan. It didn’t look to be slowing down.

“I had about two seconds to react.”

Highways England has urged drivers to consider another route home during rush hour. 

Police confirmed they were called to reports of a crash just after 4pm and have asked drivers to avoid the area. 

They have urged drivers stuck in the long queues not to use the hard shoulder because it is blocking emergency vehicles from attending. 

They would also like anyone with dashcam footage of the incident to come forward. 

Highways England tweeted shortly after 5pm confirming that southbound traffic had been released.