One of the world's most prestigious transport awards has been won by a congestion tax.
The International Transport Forum - an inter-government organisation with 54 member countries, including Australia - last week presented its annual achievement award to Milan's congestion tax, a levy imposed on vehicles entering the Italian city's central business district.
A trial of such a tax has been suggested by WA's Economic Regulation Authority as a way of dealing with Perth's traffic woes.
Under Milan's scheme, cars are charged $7.40 () per entry.
Mopeds, motorcycles, electric cars and vehicles for the disabled are exempt. Inner-city residents have 40 free entries a year and pay $3 () for every subsequent entry.
The ITF jury was told the system had reduced congestion 28 per cent, reduced demand for on-street parking 10 per cent and improved the productivity of freight deliveries 10 per cent.
The number of inner-city car crashes had fallen 26.3 per cent and carbon-dioxide emissions had been cut 35 per cent.
Under the ERA's proposal for Perth, motorists would be charged for entering the CBD during morning and afternoon peak times.
But in its submission to the ERA, the Committee for Perth said a congestion tax would be a blunt way to address a system-wide issue.
It said a charge should only be introduced after an investigation into its structure, the availability of transport alternatives and any unintended consequences.