Britain's worst traffic jam revealed as cost of hold-ups reaches £9billion

The cost of traffic jams has reached £9 billion a year, according to new analysis.

Drivers faced 1.35 million traffic jams in the past year, with billions lost in wasted time, fuel and unnecessary carbon emissions, according to transport data company Inrix.

Slip roads could be used as contraflows in efforts to relieve the pressure on overloaded motorways, under a suggestion from transport minister Jesse Norman.

The worst queue of the year happened on August 4 on the M5 northbound near Junction 20 near Clevedon, Somerset.

Traffic tailed back 36 miles at the peak of the 15-hour jam, caused when an accident involving two lorries created a fuel spill and led to the closure of two lanes.

Dr Graham Cookson, Inrix

In a letter to Highways England obtained by The Times, Mr Norman called for measures to "look after motorists", who can be caught up in delays for a number of hours with no food or water.

Analysis of queues during the 12 months to August found that November 2016 was the worst, with almost 170,000 hold-ups - 50 per cent above average.

Inrix chief economist Dr Graham Cookson said: "There are so many factors that influence congestion levels it's hard to be certain why November was the worst month.

"We do know November 2016 was significantly colder than usual, in fact, the coldest month of the calendar year.

"The risk of ice on the road can lead to slower moving traffic and people are more inclined to take shelter in vehicles over cycling or walking in cold snaps."

Mr Cookson added: "Fuel spillages, emergency repairs and broken-down lorries contributed to the biggest pile-ups this year.

"We advise motorists use the latest real-time traffic technology to keep up to date with the situation on the roads."