THE average commuter in Britain spends more than five days a year stuck in traffic.

Congestion on our roads is now 14 per cent worse than it was five years ago with Belfast, London and Manchester the most clogged-up cities.

Travelling to and from work now takes almost 30 per cent longer than it should, according to data from satellite navigation company TomTom.

London is now the 20th most congested city in the world with journey times 38 per cent slower, rising to 66 per cent in the evening rush hour.

And Belfast is just outside of the top ten global snarl up hot spots where drivers waste more than a week of their time sitting in queues.

On average the journey home now takes almost 20 per cent longer than it did in 2010 while the morning commute is now 10 per cent worse.

TomTom says it has analysed 14 trillion pieces of traffic data worldwide to produce its annual Traffic Index which shows that while Britain's road network is getting worse, the average journey time across Europe has improved by three per cent.

"People simply aren't doing enough to change their travel habits - such as working flexible hours, avoiding peak commuting times, making use of real-time traffic information and trying alternative travel modes," said Ralf-Peter Schaefer, vice-president of TomTom Traffic .

"If only five per cent of us changed our travel plans, we could improve traffic congestion on our main roads by up to thirty per cent."

In the 25 British cities studied by TomTom congestion has worsened by four per cent in the past year with only Nottingham, Portsmouth, Middlesbrough and Preston showing slight decreases.

After Belfast, London and Manchester the biggest jams can be found in Edinburgh, Brighton, Hull, Bournemouth, Newcastle, Bristol and Sheffield.

"Transport authorities are managing congestion with well-engineered policies, but you can't just build your way out of traffic jams", said Mr Schaefer. "Studies have shown that policies of ‘predict and provide' are unsustainable. Building new motorways and ring roads doesn't eliminate congestion. More must be done to better manage existing road space and to spread demand."

Globally, Istanbul has been knocked off the top spot by Mexico City where commuters in the Mexican capital can expect to spend 59 per cent extra travel time stuck in traffic during the day, rising to 94 per cent in the evening peak period - a total of 219 wasted hours a year.

The next most congested big cities worldwide are Bangkok (57 per cent), Istanbul (50 per cent), Rio de Janeiro (47 per cent) and Moscow (44 per cent).

TomTom has been collecting traffic data since 2008 and over that period, the UK city that has recorded the largest overall growth in congestion is Coventry - up 67 per cent. Stoke-on-Trent has seen the biggest increase in rush hour congestion, at 44 per cent but in Cardiff traffic flows have improved with overall congestion down 19 per cent since 2008.