London-style congestion charges could be introduced in Cardiff to curb rush hour gridlock, the county council has revealed.
The city is struggling to cope with the volume of traffic
The admission is made in Tuesday's BBC Wales Week In Week Out programme, which investigates the growing problem of traffic and pollution in Wales.
Researchers found that traffic volume in Wales had reached a level not expected for another decade.
Commuter traffic into Cardiff grows 3% a year, 50% above the British average.
It also found that while the problem was most acute in the capital - where 110,000 people commute every morning - other areas of Wales were approaching capacity.
Clive Jones, of the union Unison, said more needed to be done to make public transport more attractive to commuters.
"We need to spend far more on public transport to make it a viable alternative," he said.
Congestion charges are being considered as an option in Cardiff
With transport powers now being transferred to the Welsh Assembly Government, Professor Stuart Cole of the University of Glamorgan has called for a radical, more European rethink of policy.
"We must invest now. We have really now got to rethink what we are doing in terms of how we will move people around," he said.
"We can't keep spending money on roads. We have to look at other forms of persuading people to transfer from their cars, then we won't need to build roads."
Week In Week Out reported that the assembly government was planning to spend nearly half its £8bn budget on roads - as well as £380m of private funding for the M4 relief road.
Environmental campaigners WWF said they were dismayed.
"Climate change is a reality and traffic is the fastest growing contributor to CO2 emissions", said Welsh director Morgan Parry.
"There's going to have to be a fundamental change in the way that we think about the way we move around, and also the way government thinks about this."
Earlier this year, the UK government said it was considering introducing a 'pay-as-you-drive' road charging scheme.
Cardiff council has confirmed that there will probably be a congestion charge similar to London's, in an attempt to keep traffic levels down and and pay for better public transport.
The city is running out of space. the council has said, and doing nothing is not an option.
Former council leader Russell Goodway believes road charging in Cardiff is now essential.
"We need nothing short of a transportation revolution in which we change the entire culture of people's travelling habits," he said.
Week In Week Out - The Road to Nowhere, will be broadcast on BBC1 Wales on Tuesday at 2235 BST and repeated on Wednesday at 2100BST on BBC 2W.