Traffic jams in London 'getting worse'
Drivers in London spent an average of 82 hours in traffic jams last year, 10 hours more than in 2012, new figures suggest.
Traffic information supplier Inrix also said London was second only to Brussels in terms of Europe's most congested cities, despite the congestion charge.
It said the worst road for delays was the A4 between central London and the M4 at Heathrow, during the afternoon.
UK drivers spent 30 hours in traffic in 2013 - an hour more than in 2012.
The top 10 worst roads were in London and all were at their most congested in the afternoons.
After the capital, the most congested areas were Greater Manchester, Merseyside, South Nottinghamshire and Greater Birmingham.
Of the most congested European cities, Greater Manchester was 12th.
Overall, the UK was the sixth-worst congested country for traffic in 2013, with Belgium top (58 hours), followed by the Netherlands (44 hours), Germany and France (both 35 hours) and Luxembourg (31 hours).
Inrix president and chief executive Bryan Mistele said: "While bad news for drivers, the increases in traffic congestion in Europe are signs of a slowly recovering economy."