Heavy snow and freezing temperatures caused travel chaos across Britain today, and conditions are expected to worsen overnight.
The Highways Agency warned drivers to consider whether their journey was essential, as people in areas that escaped the snow today await heavy falls overnight.
Forecasters are warning of heavy snow showers for the south-east, with temperatures down to -3 C. Up to 30cm could fall in the western Home Counties and even colder weather is forecast for later in the week, with -6C expected on Thursday night.
Road, rail and air travellers were all hit by the wintry conditions, with Liverpool, Manchester and Leeds Bradford airports having to close for the first part of the day.
There were also delays at Aberdeen, Glasgow, Gatwick, Durham Tees Valley and Newcastle airports.
Budget airline easyJet was among a number of airlines badly affected by the weather, having to axe more than 40 flights.
A lorry driver died in a collision on the M60 in Greater Manchester, while a driver escaped unhurt after his car was hit by a train when it skidded on to a level crossing in North Yorkshire.
Many bus services were disrupted in Liverpool and most Manchester buses were off the road for the evening rush hour.
Many rail services in Scotland were disrupted by the conditions, while there were delays and cancellations to trains in eastern England.
A section of the A66 in Cumbria was among the roads that had to close, while side roads in Manchester - one of the worst-hit places - were deep in snow.
Bus services were suspended in Sheffield and other parts of South Yorkshire, while a number of roads in the Scottish Highlands were shut.
The driver who was killed was in an accident near Bredbury, and another driver received minor injuries.
The level crossing incident happened in Selby as a 44-year-old man from South Duffield, North Yorkshire, climbed out of his Ford Mondeo before it was hit by a Hull to Manchester train.
Police said the man, who was treated for shock at the scene, probably tried to brake as he approached the crossing and skidded on the snow.
The driver of the train saw the obstruction and slowed down before the impact.
Ten London-Leeds train services on the East Coast Main Line had to be cancelled and a combination of heavy snow and signalling problems meant there were delays to services on a number of routes.
The Association of Train Operating Companies said it was liaising with Network Rail and preparing to run "ghost" trains and de-icer trains through the night to keep the tracks and overhead cables free of snow and ice.
A series of road accidents added to the problems for drivers, with conditions particularly bad in Yorkshire, Greater Manchester, Northumberland and Scotland.
By 1pm the AA had attended around 9,000 breakdowns since midnight and predicted its day-end total would be around 16,000. This compares with around 9,000 for the whole of a normal Tuesday.
The AA's busiest areas were Manchester, Liverpool, Warrington, Leeds and Stoke.
The Highways Agency said: "Drivers are being advised to consider whether their journeys are essential before travelling for the rest of today and overnight into Wednesday as continuing snow and freezing temperatures are forecast for many parts of the country."
Liberal Democrat transport spokesman Norman Baker MP said: "If other countries can cope with sub-zero temperatures then why is it that the British transport system comes near to collapse at the first sign of a snowflake?
"I have travelled by train from Stockholm to the Arctic Circle and arrived 10 minutes early. We need a transport system that passengers can rely on and works all year round, whatever the weather."
Channel Tunnel services, badly disrupted before Christmas due to problems with Eurostar trains, were delayed today after a problem with a Eurotunnel freight shuttle train in the tunnel.
As well as delaying Eurotunnel's passenger and freight shuttle services between Folkestone and Calais, the incident also caused a 50-minute delay to one of Eurostar's London to Paris services.
A Eurostar spokesman said: "The freight shuttle is on the move again and our train, which left London at 2.04pm, is continuing to Paris."
The incident led to Eurotunnel passengers at Calais having to queue in their cars as snow fell in northern France.
One of those waiting was south London charity worker Ben Summerskill returning from spending the festive period in Burgundy in France.
He said: "I got caught up in queues for five-and-a-half hours on the way to France before Christmas and now I'm having further delays."
The Welsh Assembly Government said it was providing some councils with extra salt for the trunk road network, leaving them with more salt for local roads.
It holds stocks of salt for motorways and said it had enough to cope with a hard winter of prolonged cold temperatures with an additional contingency reserve.
Deputy First Minister Ieuan Wyn Jones said: "We fully understand the pressures local authorities are under due to the severe weather.
"We will do what we can to assist those who require additional stocks of salt on a priority basis, even though the government's responsibility is to maintain the trunk road network."
Wales's chief medical officer said people should take simple steps to stay safe and protect their health.
Dr Tony Jewell said: "For many people, particularly, older people who may spend a higher proportion of their time at home during the winter months, the cold weather can have a severe impact on their health and quality of life.
"It is important to see if elderly relatives and neighbours are coping during the cold weather."Reuse content