Traffic was brought to a standstill on long stretches of the road running through Yorkshire and Greater Manchester in the early hours of Friday morning, with some drivers said to have abandoned their cars.
National Highways North-West estimated at one point congestion on the eastbound carriageway between Rochdale and Saddleworth stretched to around eight miles.
The agency said there are now at least three-hour delays eastbound between Rochdale and Huddersfield and delays of at least 90 minutes on the westbound carriageway between Huddersfield and Saddleworth, where two lanes remain closed.
Simon Peach, the PA news agency’s chief football writer, has been stuck on the road for more than seven hours after covering Manchester United’s Europa League match at Old Trafford in Manchester on Thursday night.
He said: “I’ve moved about 25 miles over the course of the night, and the first 15 miles or so were clear, so I’ve been at a standstill for a really long time.
“Since I arrived I’ve seen maybe two or three police vehicles and a couple of travel vehicles. A road sweeper came along once or twice but they haven’t been able to clear the roads properly.
“I’ve never had to drive through anything like this before. My drive home would usually be about an hour and a half, the most it has ever taken me is two and a half hours. I could have flown to New York in that time.
“According to my watch it’s currently minus 1C, I think at one point it dropped to minus 4C, but according to my weather app it feels like minus 7C.”
Video journalist Richard McCarthy was in Manchester to cover the same match.
He had just arrived home after 7am having been stuck on the motorway for more than seven hours.
Mr McCarthy said: “The worst bits are around Huddersfield. There a couple of highway patrol men gave me a push when I was stuck, but said they couldn’t promise that the road ahead would be more clear. Thankfully it was.
“I saw lots of abandoned sports cars, one Jaguar left on the road with a shovel stuck in the ground next to it and no driver.
“There were lots of lorries losing momentum and getting stuck.”
Emma Hamilton, 28, who works for the NHS said she had been stuck for eight hours travelling from Manchester.
She said: “There’s lorries broken down all over the road across all lanes. Drivers are having to work out themselves how to go round them. Sort of bobbing and weaving round them.
“Some lorries have stopped to help other lorries too. I’m trying to get home from the Man United game last night. The traffic was fine on the way there yesterday as there wasn’t as many cars on the road and I set off in good time to allow for the weather.
“I’m just tired and upset at the lack of any direction from authorities. We’ve all sort of been left to it to direct ourselves. We had the gritter pass us once about 3am and they ploughed about three times then too but nothing since.
“It honestly feels never-ending at this point.”