The nation's rail and bus network may serve those who live in cities and suburbs but effectively ignores around one in five adults in modern Britain.

And even among those who do have some access to public transport, up to 1.5 million need to use three different buses, trains or trams to get from their home to their nearest town centre, said insurance giant Direct Line.

It does not just affect those going to work who then have to drive in rush hour traffic jams, it also affects those without a car who may want to go into town to go shopping, visit people or simply for a meal, cinema or other entertainment.

Just under one in five (18 per cent) have to use a car to get to their nearest supermarket and 14 per cent have no other way than to drive if they want to go to their doctor.

Wales is worst hit with 30 per cent of adults saying they cannot get to work via public transport, followed by 27 per cent in Northern Ireland and 25 per cent in the South West.

Only 11 per cent of Londoners say cannot get to their workplace using buses, trains or tubes followed, perhaps surprisingly, by 17 per cent in each of Scotland, Yorkshire and the North East.

Around one in eight (12 per cent) of Brits live more than five miles away from the nearest railway station - those in the East Midlands live, on average, 3.2 miles away but those in London live just 1.25 miles away on average.

And even those who do have access to public transport are not happy either - 20 per cent think it is too expensive and 16 per cent are dissatisfied with the service, said Rob Miles, director of Direct Line Car Insurance, who surveyed 2,000 adults.

He said: "While public transport has improved in many areas, there are still perceived issues with accessibility, reliability and quality in some places.

"This makes a large number of people dependent on their car to make short but vital trips, such as going to work, dropping the children off at school or visiting the supermarket."