Motorists are being urged to delay bank holiday getaways until after 9pm today to avoid severe queues on popular tourist routes.

There will also be severe disruption on parts of the railway network this weekend as Network Rail carries out hundreds of engineering projects.

Tourism bosses are anticipating the number of Britons making the most of the August bank holiday by taking a domestic short break or holiday will be the highest on record.

Research by the RAC and traffic information supplier Inrix suggests 16.5 million leisure journeys will take place on UK roads between Friday and Monday.

Friday is expected to be the worst day for jams as five million drivers embarking on journeys for a holiday or day trip battle for road space with commuters.

Roads are likely to be busiest between 11am and 6.30pm.

The longest delays are predicted to be on the M25 anti-clockwise from Junction 4 at Orpington/Bromley to Junction 1 at Swanscombe/Dartford at around 3.15pm, with journeys taking 55 minutes longer than normal.

Routes to coastal resorts and countryside beauty spots are also likely to be among the busiest.

The best time to be on the road will be after 9pm, but that will be too late for millions of people travelling long distances.

RAC patrol of the year Ben Aldous said: "For many people, this coming weekend is the last chance to enjoy a long weekend this side of Christmas.

"With the weather improving, that's likely to mean a lot of cars on the road heading to popular tourist destinations.

"A lot of the breakdowns we expect to see this weekend are preventable, so it's vital drivers check over their car before setting out."

Network Rail is carrying out 448 engineering projects over the weekend.

The Government-owned company said it carries out significant projects over bank holidays as "far fewer people" use the railway at those times compared with a normal working day.

A survey by tourism agency VisitEngland indicated that 8.6 million Britons are planning an overnight trip in the UK this weekend.

This is up from 7.3 million for the August bank holiday in 2018 and is the most since the research began in 2012.

Among the popular events on this weekend are Notting Hill Carnival in west London; Edinburgh Fringe festival; Reading and Leeds Festivals; Manchester Pride and Creamfields, near Warrington in Cheshire.