New research has found that congestion on British roads has jumped 40 per cent in just four years, causing the UK's network to grind to a halt.
Traffic is causing chaos in many British cities, but London is by far the worst. Last week, cars and vans were taking up to 11 minutes to travel about 350 yards on bridges over the River Thames.
Drivers in London also spend about 101 hours per year stuck in rush hour traffic, which equates to about 12 working days.
The figures were put together by a company called Inrix, which uses real-time traffic data to establish average speeds and congestion levels.
The recent jump in congestion is believed to have been caused by a sharp increase in the number of vans delivering internet shopping, the growth of minicab-hailing companies such as Uber and poorly planned roadworks.
The increased segregation of cycle lanes that are eating into the space available for cars on the road has also contributed to the disruption.
Transport for London figures, which have been released separately, show that many bus routes in the capital average less than 5mph. To put that in context, the average walking speed is 3.1mph, while a horse and carriage travels at about 4mph.
"Britain's roads are grinding to a halt and millions of people waste countless hours in needless traffic," he said. "It's bad for our economy and bad for people's quality of life. Motorists pay £33bn in taxes to the government but aren't getting the investment we need in our creaking road network."