Drivers warned to pack plenty of patience for the Bank Holiday

Heavy jams are predicted as an estimated 18million vehicles take to the roads.

The Highways Agency has warned of severe congestion around 39 sets of roadworks across the country.

Motorists are expected to travel an average of 77 miles this weekend, with main routes predicted to be more busy than the last August Bank Holiday.

Many are expected to take advantage of the forecast sunny spell and head to seaside resorts and holiday destinations in the South West and the Lake District.

According to the AA, more than a third of Britons will be heading to the beach, with Brighton, Bournemouth and Blackpool being the most popular destinations.

One in five will spend the long weekend away and 17 per cent of us have organised day trips, to make the most of the last public holiday before Christmas.

Although some will start their journey today to avoid the worst jams, tomorrow will be the busiest day to travel.

Some of the worst affected roads will be around Heathrow, Gatwick and Stansted airports, with the M6, M1 and M25 also likely to be gridlocked.

The M1 between Junctions 31 and 32 near Rotherham will be worst affected due to narrow lanes on both carriageways and a 50mph speed limit during a major widening project.

There will also be heavy restrictions on the A1 in the East Midlands around Blyth and the A66 around Scotch Corner.

Motor insurer Esure has predicted that 6.2million will face delays of an average hour and a half.

In an attempt to avoid the chaos altogether, a record number of holidaymakers-have booked tickets for Eurostar highspeed trains to the Continent.

More than 153,000 are to travel from Waterloo station in London or Ashford in Kent to Paris and Lille in France, or Brussels in Belgium this weekend.

That is a seven per cent rise in passenger numbers from the previous record set last August Bank Holiday weekend.

Eurostar spokesman Simon Montague said: "We'll be carrying the same number of travellers as would fill 1,000 short-haul jets.

"Holidaymakers are realising that Eurostar is a more convenient, more reliable way of reaching the Continent."

The AA's Patrol of the Year, Adam Ashmore, warned motorists: "A number of major events and festivals that may cause congestion are also scheduled for Bank Holiday weekend.

"It is always good advice to plan your route before travelling and to leave plenty of time for your journey."

Drivers and passengers are also advised to take plenty of water and refreshments with them on their journey in case it takes longer than planned.