Motorists are being warned to expect traffic jams as thousands of people get set to make journeys this bank holiday weekend.

Drivers embarking on a bank holiday getaway by car are being urged to set off after 9pm on Friday to avoid severe queues on popular tourist routes.

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 at their busiest until 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.

A northbound stretch of the M6 from Junction 18 at Northwich/Chester to Junction 24 at St Helens is estimated to have 54-minute hold-ups at around 2pm.

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."

Trevor Reed, transportation analyst at Inrix, said: "Bank holidays have historically been one of the busiest times for road trips, and this year drivers could even see record-level travel delays."

Highways England said it is keeping 97 per cent of England's motorways and major A-roads free from roadworks this weekend.