Has the train finally left the station?

That has to be the question now that Uncle Sam has formally announced its intention to offer up some $1.55 billion in support for the transit system supported by Mayor Mufi Hannemann and his administration.

No matter how you cut it, that's a lot of bucks. Not enough to cover the nearly $6 billion cost of the project, but big enough to make this a juggernaut difficult to stop.

Or is it?

In recent days, Gov. Linda Lingle has demonstrated remarkably cold feet about the entire project. This matters because while it is a city effort, it requires state approval in the form of an evironmental impact statement to proceed.

Lingle has not said specifically what she will do, but she has raised questions about both the financial viability of the system as well as its design and aesthetic impact on the city of Honolulu.

The financial argument has now lost ground, since the federal government seems inclined to support the project and commit vitally needed transit funds to its construction. This doesn't completely wipe out the money argument, of course, since a big chunk of the financing will come out of local taxes.

And, as everyone well knows, this source of bucks is far from a sure thing. The last time a transit project almost got approved, it was based on assumptions of tax collections that turned out to be severely optimistic.

Now, it is no one's fault that events such as the oil crisis or 9/11 came along to carve a big hole in local tax collection projections. But these things do happen and could happen again.

Still, the job of government planners is to make their best guess and then move ahead. If every project was held until the last penny was in hand, nothing would get done.

But if the money issue is moving toward resolution, the aesthetic issue remains troublesome. Many local architects have questioned — albeit at a fairly late date in the going — about the wisdom of building an elevated rail transit line through the heart of Honolulu.

Outside of urban Ho- nolulu, a sleek 21st century elevated line might be acceptable — even thrilling in some areas. But it is worth debating, even at this late date, whether an elevated skyway makes good urban planning sense in the dense and environmentally fragile urban core.

San Francisco, for instance, learned this lesson the hard way. To improve traffic flow, the state built the massive Embarcadero Freeway along the waterfront. Traffic moved a bit better, but the city was cut off from its historic and beautiful waterfront.

In 1989, Mother Nature intervened with an earthquake that damaged the freeway almost beyond repair. It was torn down and a vibrant revitalization of the waterfront followed. Uncounted millions of dollars in property values were captured when the connection between land and the sea was once again established.

Now, Honolulu's connection between the city and the harbor is far from perfect. Nimitz Highway and an ugly string of industrial facilities ensure that. But there are possibilities.

Now that the money appears to be flowing, it might be time for the city to look closely at the aesthetic issue and consider whether there is an alternative that would move people and at the same time improve the historical bond between town and harbor that is so special.