Even for the quick and the nimble, driving in Rome has never been anything but a chore. At the best of times, it's a smog-choked labyrinth of buzzing mopeds, toddling grannies and chugging Fiats vying for cobblestone space. Add in a penchant for stopping dead in the middle of an impassable street to make a delivery or exchange pleasantries with passersby, no matter how many cars may be impatiently honking, and you have the very picture of automotive chaos.

Now a new nemesis has come to town: the SUV, or soove. For a sense of what the arrival of these behemoths portends for the city, imagine one of these monsters negotiating the twisting, narrow streets in the ancient neighborhood of Trastevere--the via dei Salumi, say. This particular passageway is a challenge even for a mini Fiat 500, for it features a series of very sharp turns around the unforgiving stone foundations of some of Rome's oldest buildings--gaily colored by the paint from scraped fenders. Along the way lies da Enzo trattoria, a cafe whose tables quaintly spill into the street, offering a sort of alfresco-dining/obstacle-course experience that can be as unnerving for drivers as for the diners who often have to get up and move their chairs and tables (plates of pasta in hand) so cars can pass.

I witnessed a mind-boggling snarl just the other day. A driver had managed to wedge his Hyundai Santa Fe (which isn't even that big) between a brick corner and a badly parked Smart, a DaimlerBenz scarcely bigger than a suitcase. As he struggled to get clear, every available space around him filled with mopeds, mamas pushing strollers and local merchants shouting advice. Soon, at least a dozen cars (including several more sooves) had backed up along the street in a chorus of horns and human howls. Finally a group of men picked up the Smart and bounced it out of the way, releasing the SUV so it could tackle the next intersection--where the driver had to back up twice to turn the corner. The whole ordeal took the better part of an hour and was a perfect example of the clash between ancient and modern Rome. Ancient won, clearly.

SUVs are not just an inconvenience. They are a menace. If Rome were America, there would be a massive class-action suit by unwitting pedestrians struck by the mirrors of passing SUVs. Everything about Rome is wrong for big vehicles: parking spaces are a fraction of the size of SUVs, which means they take up a space and a half and upset the whole parking equilibrium. Yet it seems almost everyone in town is ditching their Fiats and Smarts and opting instead for big, wide vehicles--clearly a status symbol rather than a necessity, given that this is a country where most families have just one child and carpooling is unknown.

As a deterrent, the city has deemed them to be heavy polluters and plans to levy a tax of 1,000 euros on SUVs registered to city-center addresses. But that seems to be having little effect. Rome's motor-vehicle department reports that 10,000 new SUVs have been registered to residents in the last three months alone. Is this logical? Rome's streets were designed for horse carts and pedestrians. Quite literally, there's no place in Rome for an SUV.