Motorists have been facing major traffic jams as the Easter Bank Holiday weekend getaway gets under way.
EASTER TRAVEL HOTSPOTS
Heavy holiday traffic
M1: J21-J26 northbound
M4: Westbound from London
M5: Southbound from Bristol; northbound through Midlands
M6: West Midlands, Liverpool and Manchester
M25: J15 and J16 near Heathrow; J20 and 21
M1: Contraflow J81J10
M6: Southbound onto M5; contraflow J12-J13
M25: Holmesdale Tunnel
Drivers on the M1 northbound out of London, the M60 in Greater Manchester and the M42 east of Birmingham were all facing long delays.
The UK's airports have also been busy, with a record 2.5m Britons planning to spend Easter abroad.
Heathrow dealt with 212,000 passengers on Thursday, making it the airport's busiest day of the holiday period.
The airport operator BAA said it was also expecting 600,000 people to travel from Gatwick from Thursday to Tuesday.
BAA warned that passengers would need to be aware of the continuing baggage restrictions.
Air travellers are still banned from carrying liquids in containers larger than 100ml in their hand luggage, BAA said.
There are no limits on the size of containers of liquids in baggage to be checked in, it added.
AA Roadwatch said the height of road congestion had been on Thursday afternoon, with traffic easing into the evening.
However, motorists on the M60 in Greater Manchester were still facing jams anticlockwise between J24, Denton Island and J23, Ashton Under Lyne, because of a serious accident later in the day.
Crash causes delays
Drivers were also stuck in jams on the M42 east of Birmingham after a crash between a car and a motorcycle between junctions 7 and 8 at around 1645 BST.
Two people died in a crash on the M6 near Alsager in Cheshire which also caused huge tailbacks for northbound vehicles on Thursday morning.
A spokesman for AA Roadwatch said: "The worst was in the afternoon, with the busiest areas on the routes out of London, such as the M25 and the M1.
"Although Friday should be quieter, Monday evening could be quite bad as everyone plans to come home after the break at the same time."
The AA said it expected to deal with 11,000 breakdowns by the end of Thursday.
On the railways, there were delays to Virgin Trains services through Lichfield Trent Valley on the west coast main line as well as Central services around Birmingham and First Great Western services from London to Slough, Berkshire.
Engineering work is planned for sections of lines on a number of routes during the Easter holiday period.
Temperatures are expected to hit highs of 20C (68F) in London on Thursday and Friday - as hot as Marrakesh in Morocco, and hotter than many Mediterranean resorts.
The whole of the UK is expected to experience its fair share of sunshine, with temperatures in the mid-teens in most places.