Motorists are being warned to drive with care after freezing conditions in England led to a series of accidents.
No-one is thought to have been hurt but a 25-mile (40km) long section of the A1 northbound in North Yorkshire was shut on Monday morning.
Some drivers said they were stuck for four hours following a number of collisions involving jack-knifed lorries and other vehicles.
Schools have also been affected with about 55 closed in Essex.
A total of 39 were closed in East Sussex with a further 19 closed in Kent and Medway.
A handful of schools were also closed in the East Midlands, Warwickshire, Surrey and Yorkshire.
Severe weather warnings are in place across England with ice posing a major hazard on roads and pavements.
Some rail services continued to suffer following the weekend's big freeze.
Southeastern hoped to operate a normal timetable, but said cancellations and delays were "very likely".
In Portsmouth a broken-down train and electrical supply problems caused delays, disruption and cancellations to South West Trains services.
Passengers had to switch to buses to get to Portsmouth, while rail services on the busy routes to and from London Waterloo were hit.
In a statement, the operator said: "These low temperatures are set to continue for several days. Please take care when travelling and allow additional time for your journeys."
The weather also lead to flights being cancelled or delayed.
Heathrow Airport axed half of all flights on Sunday night but the airport, which had 2.4in (6cm) of snow, hoped to resume normal service on Monday.
A spokeswoman said: "We are expecting everything to operate as our normal schedule. There may be some cancellations and reshuffling as a result of yesterday's disruption."
With only 50% of the 1,300 scheduled flights going ahead on Sunday, many travellers faced a night sleeping on terminal floors.
But Heathrow insisted its "snow plan" had worked "far better" than in previous years.
A spokesman said: "We took the decision with airlines and air traffic control yesterday to reduce the flight schedule in advance.
"By cancelling flights in advance, airlines have been able to re-book some people on to flights that are departing, and passengers have had better quality information about whether they can fly or not."
The airport faced heavy criticism following severe weather in December 2010 when it almost ground to a halt.
Forecasters warned of continuing icy conditions as temperatures hovered around freezing in many areas on Monday morning, although Church Fenton in Yorkshire recorded -8.6C (16.5F) with visibility less than 100m.
At the weekend scores of travellers were caught up in the conditions as airports closed runways and rail services were delayed.
Drivers were trapped in their cars on the M40 and M25 and elsewhere roads were gridlocked as a result of accidents and jack-knifed lorries.
Tube lines also faced disruption and football matches and horse races were called off.