Warm weather is forecast for May bank holiday

Sunny spells over the bank holiday weekend are expected to bring gridlock and train travel misery to millions of Britons.

Weather forecasters say temperatures may reach highs of 23C (72F) but the AA has predicted that about 18 million vehicles would begin clogging up the roads from today.

Chaos is also expected on the railways with travellers on the West Coast Main Line in the Midlands and those heading to London's Liverpool Street Station facing disruptions and station closures.

Engineering work on the West Coast Main Line at Nuneaton, Milton Keynes, Rugby and along the Trent Valley will mean there will be no Virgin Trains service to or from Euston station in London over the three-day period with trains only running as far south as Coventry or Birmingham.

Yet again, Liverpool Street mainline station will be closed on Sunday and Monday for major bridge work, while services in south London will be disrupted by points renewal work at Clapham Junction.

Network Rail chief executive Iain Coucher, whose company was fined a record £14m for engineering overruns at New Year, said: "The work over the May bank holiday is all about improving the railway for passengers and freight users. Over the long weekend, we'll be investing millions of pounds to make services more reliable, more punctual and, in some cases, faster and more frequent.

"While the overwhelming majority of services remain unaffected, our message to passengers is to check before you travel."

The picture did not look happier on the roads with the RAC predicting congestion hotspots around out-of-town DIY stores, with an estimated 86 per cent of homeowners likely to visit home improvement stores at some point over the three-day holiday.

Jams were also expected on routes to the west of England, from northern England to north Wales, in the Lake District, Blackpool, Brighton and Bournemouth as well as in the Midlands and Norfolk.

The AA said that all major routes were likely to be "significantly busier than normal" tonight with the average journey averaging about 135 miles, as many commuters headed for the coast, home or to airports and ferry ports. The association said it was expecting to deal with 55,000 breakdowns over the weekend.

Airports are also likely to be busy with more than 1.3 million people likely to pass through Heathrow, Gatwick and Stansted. Passenger numbers will peak today with 187,000 people setting off from Heathrow. A BAA spokeswoman insisted that Terminal 5 was operating well, despite its disastrous opening in March.

Popular May Bank holiday destinations this year include New York, Dublin, Amsterdam and Rome, with those seeking guaranteed sun opting for Orlando in the United States, Faro in Portugal, and Tenerife and Alicante in Spain.

Paul Knightley of MeteoGroup predicted that the higher-than-average temperatures, reaching a maximum on Sunday of 23C (72F), would continue for the rest of the week.

Areas to avoid

Road blackspots

M1 Bedfordshire J6A-J10 – narrow lanes and contraflow

M1 Nottinghamshire J27-J28: narrow lanes and speed restriction

M11 Essex J5-J6 and J8-J9: narrow lanes and speed restriction

M25 Kent J3-J1B narrow lanes

M27 Hampshire J11-J12: narrow lanes and speedrestriction

M4 South Wales J30-J32: contraflow

Busy spots near out-of-town stores

A23 Purley Way, Croydon, south London

A406 North Circular at Brent Cross and Edmonton, north London

A13/M25 interchange, Essex

A635 Manchester Road, Ashton Under Lyne, Great Manchester

Rail Engineering works

West Coast Main Line work at Nuneaton, Milton Keynes, Rugby and along the Trent Valley means there will be no Virgin Trains service to or from Euston station in London on Saturday, Sunday and Bank Holiday Monday.

Liverpool Street main line station in London will be closed on Sunday and Bank Holiday Monday for bridge work. There will also be points renewal work at Clapham Junction station in south London.