The gridlock on British roads is costing UK businesses £20 billion a year in lost productivity, a survey has calculated.
The study by the Institution of Civil Engineers said employees arriving harassed and late for work were costing companies dear.
Congestion also meant freight companies had to allow for longer and unpredictable journey times, so increasing the costs of goods and services to the public.
Between 1982 and 2003, the number of cars on UK roads rose from 15.5 million to 26.2 million – a rise of 70 per cent – increasing the pressure on the nation's transport infrastructure, it warned.
Increased car use was also leading to greater air pollution – in 2002 90 per cent of UK transport emissions came from the motorcar, the ICE calculated.
The survey also found strong support (69 per cent) among the general public for improvements in public transport to curb the nation's love affair with the car.
ICE president Colin Clinton said: "Unfortunately, there's not one simple solution to combat road congestion. We're pleased that the public backs improvements in public transport, but the real battle is getting motorists to use it.
"As civil engineers, we're not naive enough to expect the end of the car-first culture overnight.
"However, action must be taken before we can't drive to work or school in the morning due to permanent traffic jams outside our houses," he added.
Among its recommendations, the institution is backing the controversial issue of road pricing as an effective way of getting motorists to think more about using public transport.
"Pollution and the continued rise in the number of cars is a damaging scenario for our environment," said Clinton.
"There will always be essential car journeys, but with a quarter of car trips in the UK being less than two miles, ICE believes the majority of these can be made by public transport, walking or cycling.
"We've got no option other than the carrot and stick. The carrot option is to encourage increased bus, train and tram use, the stick option is to charge drivers to use highways.
"Ultimately, the future of UK roads is simple – increased governmental promotion of public transport or meltdown," he concluded.