An accident caused a tailback on the M5 near Bristol
Train travellers in the UK are facing disruption over the Easter weekend as Network Rail carries out major works on key routes.
The main projects are on the East Coast mainline and the West Coast mainline, where work over-ran at New Year.
Some of the busiest routes have fewer than one train per hour. Cross-Channel ferries at Dover are also delayed due to high winds and heavy traffic.
Roadworks, high winds and predicted snow may also lead to travel chaos.
Weather forecasters have said there is a chance of snow in Scotland on Good Friday, which may spread south over the weekend.
They have predicted up to 2cm (0.8in) of snow in eastern England and 5-10cm (2-4in) in northern Scotland on Saturday.
West Coast main line: Closed Good Friday-Easter Monday between Coventry, Rugby and Northampton and from London Euston Sat - Monday
East Coast main line: London King's Cross - NE England and Scotland services diverted via Leeds, 1400 Sat - 1400 Sun
Great Western main line: Didcot Parkway - Swindon and Chippenham services replaced by a bus service or diverted, Fri-Mon
South West main line: Alterations and diversions to services to and from London Waterloo due to engineering works at Clapham Junction, Fri-Mon
East Anglia/Essex coast line: Replacement bus service between Gidea Park, Billericay and Ingatestone
Transport Scotland has warned of high winds on the Skye Bridge. The Erskine Bridge approach is closed to high-sided vehicles and the Tay Road Bridge is open to cars only.
Generally, the weather is expected to be cold and windy across much of the UK for the Easter weekend.
Police in Dover said many travellers were missing their scheduled ferries because of delays caused by high winds in the Channel, and heavy traffic.
They are warning of a three-mile queue at the eastern dock and heavy demand at the Channel Tunnel.
Bad weather and accidents, rather than volume of traffic, are reported to be causing the problems on the roads.
Queues are building southbound on the M5, north of Bristol, following an accident involving two cars. And a lane was closed in either direction on the M48 in Gloucestershire between junctions one and two due to strong winds.
The RAC said so far most roads were flowing relatively freely.
A spokeswoman said this could be down to the lack of commuters, to families getting away early to make the most of the four-day holiday, and to drivers having a lie-in.
She added many of those who set off last night were caught in various delays.
More than 30 rail projects are to be carried out over the Easter holiday, with 6,000 people working about 300,000 man-hours. The work includes laying new track, repairing bridges and updating signalling systems.
Network Rail was fined a record £14m by the Office of Rail Regulation after engineering work over-ran on a stretch of track near Rugby, causing delays for thousands of people over New Year.
Speaking at Rugby train station, Network Rail chief executive Iain Coucher said the group had "learnt our lesson" and would do "absolutely everything" to ensure train services were back to normal on Tuesday.
He said: "I can guarantee that we will do absolutely everything that we need to minimise the chance of any kind of over-run.
"We are very confident that we can do all the work we have to do over these four days."
Engineers began working on the tracks at Rugby station on Good Friday
Network Rail said information about service changes was readily available and advised passengers to double check their travel plans before setting out.
Despite the Easter getaway, the number of journeys - usually around 3.5 million a day - was expected to be down by more than half on Good Friday because most commuters had the day off.
Edward Funnel from the Association of Train Operating Companies said 80-90% of rail services would be unaffected, and the work was being carried out while fewer people than normal would be using services.
He said: "You have got four clear days to get to grip with the network and do some big serious work to improve the network, signals, new track and so on."
On other forms of transport, two million people are expected to pass through British airports this weekend, peaking on Good Friday.
At Heathrow, 187,000 passengers are expected on Good Friday, compared to 200,000 who checked-in yesterday.
The Highways Agency said two-thirds of roadworks had been removed from England's motorways and major A-roads to ease congestion.
A total of 38 sets of roadworks have been completed and a further 47 are suspended until midnight on Monday 24 March.
However, roadworks are still affecting the M1, M4, M5, M6, M11, M25, M42, M48, M55, M56, M57, M60, M62, M65, M69 and many A-roads.
The AA said 6.5 million cars were expected on the roads over the weekend.
Eurostar said it would be carrying a record 160,000 rail travellers through the Channel Tunnel over Easter.
On the London Tube, the Circle, District, Hammersmith and City, Jubilee and Metropolitan lines are affected by engineering works.