Milan's version of London's congestion charge went into effect on Wednesday, causing few of the feared traffic snarl-ups but prompting fresh claims that the city was unprepared for the scheme.
Milan is the first Italian city to introduce a pollution tax and the handling of the 'Ecopass' scheme is being watched closely by mayors in other traffic-clogged cities up and down the peninsula.
With many Milanese businesses still closed for the New Year festivities, traffic was much lighter than normal on Wednesday and so the anti-pollution initiative had a fairly easy launch.
Traffic police reported no problems with parking on the fringes of the protected zone and said their main task had been to give information to confused motorists.
But they admitted the key test would come next Monday when the city really returned to work. ''It's going to be much more hectic. Then we'll be dancing a tarantella,'' said one officer.
Off the roads, there were annoying difficulties for motorists wanting to pay their Ecopass tax by credit card via Internet or the phone line set up by the city council for this purpose.
Both payment channels were flooded with requests on the day before the new system came into effect and promptly broke down under the weight.
By Wednesday morning only a few thousand Milanese drivers had paid the tax but officials pointed out that they had until midnight on Thursday to do so.
Mayor Letizia Moratti, who has pushed the plan through despite the opposition of shopkeepers and motorists' clubs, assured Milanese people on Wednesday that the ''teething problems'' were being overcome.
She pronounced the launch ''positive'' but stressed that no real judgment could be made until the scheme had been working for a year.
The Ecopass scheme aims to reduce fine particle PM10 pollution by 30% and cut traffic volume by 10%.
80-EURO FINE.
Anyone driving a polluting car into the central area without paying the tax - up to 10 euros a day according to how 'dirty' the car is - will be automatically sent an 80-euro fine. New cars respecting the latest EU emission standards can enter for free.
On a normal working day about 90,000 cars go in and out of the centre of Milan. According to studies, when the system is up and running, about 36,000 cars will pay the fee each day.
City officials said that within an hour of the initiative coming into effect on Wednesday, some 4,500 vehicles had entered the city and about 20% of these had had to pay the tax.
''This is just a first step. As time goes by we'll see how to modify the measure and to make it more effective,'' Milan traffic chief Edoardo Croci said.
Meanwhile, opposition to the Ecopass scheme did not go away. Shopkeepers in the centre, fearful of falling business, threatened to pass this ''onerous imposition'' on to customers through higher prices.
Milan's Automobile Club said it wasn't against pollution taxes in principle but insisted that the time was not ''ripe'' for the Ecopass because first public transport should be boosted and more car parks built in the area around the Ecopass zone.
''The way it's starting off today, the initiative is hard to understand and manage. It looks like a new tax weighing on those who, for want of an alternative, cannot do without their cars''.
Opponents of the traffic levy were out on Milan's streets on Wednesday collecting signatures for a petition demanding a city referendum on the scheme.
Polls carried out recently by the media have shown that the local population is evenly divided on the Ecopass.
So far Mayor Moratti has talked tough, saying she will push ahead because her popularity is ''less important than the health of the Milanese people''.
Last month she wrote a letter to 765,000 city residents appealing to them to cooperate.
