Calls for a congestion charge to relieve Perth's gridlocked inner-city streets have grown louder, with a third transport expert publicly supporting its introduction.
Visiting city planner and author Jeff Speck believes congestion pricing is a much underused tool in reducing excessive driving and excessive congestion.
He says if motorists were asked to pay something closer to the real cost of driving, they would be able to make market-based choices about when and where to drive.
Last week the principal of transport consultants Arup, Allan Mason, said road pricing had been a success all over the world and should be considered in Perth.
RAC of Queensland senior transport economist Susan Furze told a conference in Perth in August that congestion charging encouraged road users to seek alternatives to driving during peak hours.
Mr Speck, in Perth for a public lecture this week, said cities had an obligation to free its residents from the burden of car dependence.
"When a city does, everyone benefits, including the city," he said.
He said anything that was free or cheap was often over-used.
The excessive use of cars caused congestion and a myriad of problems resulted.
Senior Perth transport planner Ryan Falconer said yesterday the decision not to introduce a congestion charge in Perth was a political one, not a practical one.
Dr Falconer said there was no doubt it was the most effective way to deal with congestion.
In his book Walkable City, Mr Speck said London was a good example of how effective congestion charges could be.
Its introduction in the early 2000s led to a 30 per cent reduction in congestion and a 14 per cent decline in journey times. Cycling among Londoners jumped 20 per cent and air pollution fell about 12 per cent.
Most of the money raised by the toll, more than $1 billion, had been spent on public transport.
"London now has hundreds of new buses, providing almost 30,000 more daily trips than before the charge," he wrote.
"Bus reliability has jumped by 30 per cent and bus delays have dropped by 60 per cent.
"London is not alone in its embrace of congestion pricing. Sao Paulo, Shanghai, Singapore, Stockholm and Sydney have all introduced similar measures with varying, but generally positive results."
Mr Speck, an architectural designer, is a member of the US Department of Homeland Security's sustainability task force.