Sydney In London, people moan about the weather. Parisians complain about doggy poo. And New Yorkers, well, New Yorkers complain about everything. But in Sydney, there is only one topic of universal displeasure: traffic congestion. Newcomers are invariably surprised that a city so blessed with physical beauty - a sparkling harbour, immaculate parks and white surf beaches - should have made such a hash of its road system. Indeed, the phrase 'road system' perhaps adds too much dignity to the nightmare of freeways, tollways, flyovers, bridges and tunnels. The issue reached a crisis point this week when the Spit Bridge - an archaic drawbridge connecting the city to the northern suburbs - jammed open for two hours, trapping thousands of commuters and causing widespread fury. Faced with a state government whose only solution to traffic congestion is simply to build another road tunnel, a leading transport planner says the long-term solution is a congestion tax. David Hensher, from the University of Sydney's Institute of Transport, does not favour a blanket congestion charge for the inner city (like that used in London), but a sophisticated, user-pays system based on the type of vehicle and time of travel. A similar system, which tracks vehicles via GPS units, will come into force in the Netherlands by 2011. Professor Hensher calculates that the new congestion tax, if approved, would cut Sydney's commuter traffic by 8 per cent during peak periods, reduce greenhouse gas emissions and save the state government the astronomical cost of new roads, bridges and tunnels. Under the scheme, motorists driving into the city during peak times could expect to pay up to 15 cents a kilometre for the privilege, while drivers using uncongested roads at non-peak times would incur no additional charge. 'Having it calculated by time of day encourages people to travel at different times of the day,' he said. Not only would such a tax be inherently fairer than the present system (since those causing congestion would pay the most) it would reduce carbon dioxide emissions by 6 per cent. 'It seems like a win-win for the environment to me,' said Professor Hensher. The proposal - radical in a city where car ownership is still sacrosanct - has naturally polarised public opinion. The state's roads minister, Eric Roozendaal, immediately dismissed the idea of a congestion tax, which he called 'armchair advice from academics in ivory towers'. But Professor Hensher's scheme has been enthusiastically endorsed by the 10,000-strong Friends of Greater Sydney lobby group. 'You can't build your way out of the problem we have because you can't build roads fast enough to accommodate the growth in population,' the group's director, Ken Dobinson, said. Trying to persuade Sydney's motoring public to willingly accept such a tax is going to prove difficult, if not impossible. Newspapers and talk-back radio shows have been inundated by hostile commuters. 'A congestion tax - that's just what Sydney's long-suffering motorists need to create a permanent state of road rage,' fumed one caller. Some say salvation might arrive in the form of higher petrol prices. But by Professor Hensher's estimates, petrol will have to reach A$2.50 (HK$18.62) a litre before large numbers of Sydneysiders abandon their cars. Given the current world oil shortage, that event may be closer than even the most boneheaded, car-bound commuter might imagine.