You may have missed this recent news item: Philadelphia has just lured a new corporate headquarters to town.

Before you get too excited, however, our new corporate neighbor is not on the order of a Boeing, which moved recently to Chicago, or some high-flying, information-age operation, or even a buttoned-down financial institution.

No, the new kid in town is Impark. Impark builds and manages parking lots all over North America. Fitting, really, that Impark chose The City of Brotherly Love to relocate about a dozen workers. Where once this city made radios and railroad locomotives, carpets and cigars, it now makes parking spaces. In vast abundance. And so it is that in Philadelphia, this parking lot conglomerate has found a perfect home.

There is, in case you haven't noticed, an epic struggle being fought right now over the very heart of the city. It pits the forces of urban dynamism, vitality and creativity against parking lots, parking lots and parking lots. They are already everywhere in the city, and more on the way each month it seems. Every new restaurant, new art space or apartment conversion seems to be matched by a new parking lot. Urban matter battling urban anti-matter.

It doesn't matter where one looks, no part of the city has been spared these cancerous spots on what otherwise might be healthy urban tissue. I can think of no other major American city whose very heart is covered with parking to the extent that Philadelphia is. Not New York, not Boston, not San Francisco or Chicago.

And now the news that Jefferson wants to develop the entire block of Chestnut Street between Ninth and 10th as a massive, behemoth parking garage. By volume, this concrete monster may prove to be second only to the Kimmel Center as the largest new structure in the city. Chestnut Street has recently shown signs of springing back to life. With this garage, Jeff will pull the plug on that resuscitation, effectively killing with concrete the revitalization of the street. Goodbye Chestnut Street -- we hardly knew you.

All cities must have some parking facilities, to be sure. The question therefore becomes: to what extent will we sacrifice other, more important uses of urban space to the demands of cars? How much parking is enough parking?

That question, however, isn't even being asked by those who decide the fate of urban real estate in this city. The mechanisms that are supposed to ensure that the city is developed to the best advantage for all of us have failed to protect the public good. In this sense, the spread of parking lots across the face of the city isn't an economic or even a design issue so much as it is a political issue.

The zoning commission, for example, which must approve all these new lots, ought to be the body that balances private interests against the larger commonweal. But it has devolved, essentially, into a trough where some of our porcine friends belly-up to feed. (No word yet on whether the new Jefferson garage will be centrally air conditioned, as zoning commission chair Tom "leave no sheet-metal worker behind" Kelley has demanded of all new construction).

City Council might step in by providing tax incentives for projects that convert parking lots into housing or other uses. Conversely, they might levy an imposing surcharge on parking lots to make it financially less appealing to build and operate these urban eyesores.

But the new parking that has spread across the city like zits on a teenager has been driven not by market demand, but by the demands of politically connected developers who can use parking lots as a cheap way to make lots of money, while waiting for their land to appreciate.

That developers should want to build parking lots comes as no surprise. Easy money is easy money. What ought to shock is that we don't hold our public officials accountable for selling Center City to the lowest bidder. Only when the political price paid by politicians is higher than the campaign contributions they receive from parking lot developers will we rein in this asphalt epidemic. It is our collective responsibility, then, to take back the city from those who would pave it over and line it.

How much parking is enough parking? Consider this: there are roughly 25 major streets that run north and south in the center of Philadelphia, and 11 that run east and west. Every single one has at least one parking facility somewhere on its length in this small, two-square-mile area. Locust and Lombard, Second and 22nd -- not one spared the ugly scab of parking lots.