Severe weather overnight is causing major travel disruption.
Amber and yellow snow and ice warnings are in place across vast swathes of the UK, with delays, road closures and stranded vehicles.
Services on trains and planes are disrupted, with travellers urged to check with their transport provider before setting off on their journeys.
The worst areas are Kent, East Anglia and north-east England, but problems are spreading.
Drivers are being advised to avoid unnecessary journeys and stick to major routes where possible if they must travel.
The AA received three times as many breakdown call-outs than normal on Wednesday morning.
The firm’s president, Edmund King, said: “We have already had more than 70 cases of drivers actually stuck in snow this morning.
“Our patrols are working flat out to pull vehicles out of the snow and to get them started.
“It looks like it will be a very busy day. The ‘Beast from the East’ has bared its teeth.”
In Yorkshire, the A61 was shut between Harrogate and Skipton due to the conditions, while further north, in Durham, the A66 was closed between the A1M and A685.
The A1 in Durham was also closed between Scotch Corner and Catterick after a lorry jackknifed.
Highways England said the A1 in Cambridgeshire had to be shut due to severe weather, between the A1M and A6121 at Tinwell.
A number of lorries jackknifed and vehicles were caught in queues for more than three hours.
In Norfolk, police also reported roads being blocked due to lorries and cars becoming stuck in the snow, including the A11 southbound at Wymondham and the A143 at Haddiscoe.
Trains
Rail passengers across Britain suffered from delays and cancellations on Wednesday, with 15 operators affected by the conditions.
The West Coast Main Line is closed between Carlisle and Scotland with no trains or replacement buses.
Alternative rail routes between England and Scotland are also severely disrupted.
Virgin Trains East Coast lifted its ticket restrictions for services on Wednesday, Thursday and Friday.
Dozens of Southeastern services were unable to run due to problems in several locations.
There were cancellations on the Medway Valley Line after train crew were unable to get to depots because of the heavy snow.
A snow clearing vehicle broke down and blocked the Ashford-bound line at Wye, while there was major disruption on metro routes between Dartford and London via Woolwich, Bexleyheath and Sidcup because of signalling faults caused by the weather.
Delays and cancellations on the c2c line from south Essex into London Fenchurch Street were worsened by freezing doors which prevented some passengers getting on and off trains.
Passengers were advised to check with operators before travelling.
Flights
Dozens of flights departing or arriving at Heathrow have been cancelled, including 54 British Airways services on mostly short haul routes.
Fifty-two flights to or from London City Airport were cancelled. An additional five inbound flights were diverted, including BA’s business class only service from New York, which was forced to land at Gatwick, West Sussex.
Newcastle Airport suffered delays and cancellations as snow was cleared from the runway.
Gatwick Airport said flights were arriving and departing as usual, but recommended passengers check with their airline ahead of travelling.
East Midlands Airport said it was fully operational, but that it would be monitoring weather updates throughout the day.