Motorists are being warned about freezing temperatures and icy roads as more snow is forecast across Oxfordshire.
Up to 20cm (8in) of snow fell over the weekend, causing traffic queues of up to eight hours on the A34.
Many rail services into and out of London remain severely disrupted.
CrossCountry routes are running revised services while First Great Western trains are experiencing delays on all routes.
Stagecoach and Oxford Bus Company are running, but with delays.
Two lanes of both the A34 and M40 motorway were open during the morning rush-hour on Monday.
Police warned drivers that they should not abandon their vehicles, especially where they might block emergency crews and major roads.
"If they do, the vehicles may have to be removed and it will be the driver's responsibility to pay for the cost of recovering them," a police spokesperson said.
Temperature 'too low'
More than 80 cars were abandoned on the A34 in Abingdon on Saturday night and several jack-knifed lorries blocked the route.
Andrew Crossland, 24, was travelling home to Doncaster from Southampton when he became stuck for 14 hours.
"I saw the queue and then started listening to the radio and I was like 'Oh dear this doesn't sound so good'," he said.
"There were loads of big HGV lorries storming past at 60mph with out a care in the world. It was frightening really."
The county council said that despite gritters working around the clock, the temperature had been too low for the salt to be effective.
Military flights to RAF Brize Norton are running to schedule.
Gp Capt Dom Stamp said there had been a request from Heathrow Airport to take some flights on Saturday.
"We weren't able to take any from them because we simply wouldn't have the ability to park them and to handle them and obviously our output was what was crucial to us, our military output, providing the air bridge so we had to concentrate on that."
Many public toilets across the county were also closed because of frozen pipes.