Britons are heading into the bank holiday weekend facing a familiar scenario of congested roads, busy airports and disrupted rail travel.
The RAC said up to 11 million Britons will take to the roads over the holiday period, with all major routes getting busy.
On the railways, passengers face travel difficulties on many lines as Network Rail (NR) carries out extensive engineering work.
Some passengers will have to take buses instead of trains, but rail watchdog Passenger Focus said customers would rather have a longer train journey than have to take a bus.
Shadow transport secretary Theresa Villiers said bus replacement services were "often the worst and most unpopular option for rail users".
On the London Underground, only four Tube lines will run normal services this weekend. Two lines - Victoria and Waterloo & City - will close completely, while there will be part-closures on five others.
Numbers flying away are normally lower for the May Day bank holiday than for other bank holidays linked to school holidays or half-term breaks.
But Gatwick airport said around 325,000 passengers will be using the airport up to Monday. Malaga in southern Spain is the most popular destination, followed by Dublin and Orlando in Florida.
Those staying at home can expect some reasonable weather over the holiday period, at least in the southern half of the country. Temperatures should reach around 17C (63F), with southern England getting mainly dry conditions. But northern England, Scotland and Northern Ireland can expect some rain.
Busiest routes are expected to include the M4, M5 and A303 into the West Country and Wales, the M6 and A590 to the Lake District and the M55 to Blackpool.
