Anyone worried that the Great Seattle Transit Debate will subside, once Sound Transit's light rail opens this weekend, can rest assured that the controversy will not go away. It will just rise to a new plane: how does it work, as opposed to how might it work?

A good example of the new debate is a story in today's Seattle Times, about parking, and its lack, around the stations. Transit fans are about to discover one of the awkward tradeoffs in siting these stations: only one of the 14 stations (the Tukwila one) has a park-and-ride lot. For the others, if you intended to drive your car to a station, park it, and ride in style to downtown, you're in for a shock.

The planners, yielding to concerns of shops and residents near the stations, as well as the anti-auto lobby, chose not to build or encourage parking lots at the stations. This is meant to encourage walking, biking, a bus transfer, or even moving to a home nearby. In the name of encouraging walkable neighborhoods and other good things, there will be lots fewer commuters on those trains. In other cities, these train stations are often surrounded by ugly acres of parking (as with many bus park and ride lots, of course), and Sound Transit wanted to avoid such car-worship.

Ah, but what if those retrograde auto-addicts decide to park on nearby neighborhood streets? Once again, the transit planners are out in front of the problem, issuing permits to locals for such parking, backed by stiff $44 fines for commuters who try to avoid the two-hour limits. Of course, this means local businesses and residents have to pony up for such permits and figure out how customers and employees cope with the sudden loss of free parking.

All this suggests that the main problem with light rail would be success. Areas around stations will be upzoned, driving up property taxes and increasing traffic. Feeder buses will flock to once sleepy commercial districts. Small shops will be driven out. (And did I mention screeching sounds from wheels on rails?) Of course, Sound Transit will also be damned if it doesn't — appeasing the neighborhoods will mean low ridership figures and criticism for costs.

Retrofitting a grown-up urban area with rail (as opposed to building it early and letting growth cluster around it later) is full of high costs and hot tempers. Bus routes are cut to deflect money to rail and to drive passengers to rail. Light rail, as the adjective suggests, means relatively low capacity and slow speeds. The initial routes, being politically selected, don't attract as many users as usually projected. And the claim that transit stations will shape growth and create walkable, complete neighborhoods is, while true over a long time, very hard to pull off in any dramatic way.

Shaping growth is perhaps transit's best benefit, but it's very hard to do in practice, particularly in regions like Seattle where planning powers are weak. The Tukwila location, for instance, is particularly bad, a result I'm told of the refusal of Tukwila town fathers to allow the station along Route 99 or where there is some commercial activity. There are no natural nodes for development along the Rainier Valley route.

In phase two, there are some better opportunities, particularly in turning Lynnwood into a new city and along the route from Bellevue to Redmond, now mostly warehouses. The Bel-Red corridor is also constructing stations quite close together, a key to stimulating transit-oriented development as in the Arlington, Virginia corridor for DC Metro. Already there are anxieties in Bellevue that the corridor will bleed away commercial vitality in Bellevue. That's both a good sign that the Bel-Red corridor will actually work, and a warning sign of gathering political and commercial resistance. The debates will never end.