Severe weather overnight has caused major travel disruption, with more expected throughout the morning.
Amber and yellow snow and ice warnings are in place across vast swathes of the UK, with delays, road closures and stranded vehicles expected.
Trains and planes were also likely to be affected, with travellers urged to check the latest situation before setting off on their journeys.
Here are some of the latest reported issues:
Several roads across the country have been left impassable following heavy snowfall overnight, forcing police to close large sections of major routes.
In Yorkshire, the A61 has been 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 jack-knifed.
Highways England said the A1 in Cambridgeshire had to be shut due to severe weather, between the A1M and A6121 at Tinwell.
The closure caused long tailbacks overnight.
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.
National Rail has warned of further disruption to services on Wednesday.
TfL Rail, London Overground, c2c, Southeastern, Greater Anglia, Southern, South Western Railway and ScotRail all warned of the potential for cancellations or delays to services.
Passengers were advised to check with before travelling.
Great Northern was expecting to run a normal service, weather permitting.
Isle of Man Transport tweeted that all services were currently suspended.
Some flights have been cancelled from Heathrow, including a number of British Airways services.
London City Airport also said there would be some disruption to services, while Newcastle Airport said there could be some delays while the runway was cleared of snow.
Gatwick Airport said overnight that 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.