COUNCILMAN Peter Steinbrueck says he is for the waterfront tunnel or nothing. If Seattle cannot afford to replace the Alaskan Way Viaduct with a tunnel, he says, it would be better to replace it with nothing.

He is not alone in this view. Many motivated by aesthetic concerns share it, but we do not.

We are for a tunnel if the city can afford it. If not, we are for a new viaduct. The viaduct is the central link in the former U.S. 99, the second-most-important north-south artery in our city. Whole areas of Seattle rely on Highway 99, as do other parts of the region, and in the 21st century the region will need its capacity even more. The city cannot tear down the most efficient segment of it and replace it with nothing, or a stoplight-cluttered city street. As a bypass, its function cannot easily be replaced by transit.

There are two basic choices: above ground or below ground. The purpose of putting the highway below ground is to beautify what Mayor Greg Nickels calls "Seattle's front porch" and make the waterfront attractive for downtown living. That is a fine goal. It will make the city better. But it is not a transportation goal.

We understand an architect's revulsion at replacing the old ugliness with new and sturdier ugliness. The viaduct mars our city. It also enables our city to function. Like a string of telephone poles, it is ugly but useful.

Put it underground if we can afford it, but in any case, replace it with something that works.