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Seattle should build a bridge over troubled waterfront
Special to The Times
With the governor's June 9 appointment of a panel of experts to review the Alaskan Way Viaduct and Highway 520 bridge-replacement projects, the stage is set for the group to report by Sept. 1 on whether those plans are achievable.
At least this would be the case were the city of Seattle and the Washington state Department of Transportation "plans" complete and compatible.
City leadership is polarized. Some City Council members and the mayor are at odds over what to do, both as to preferred alternatives as well as whether to let citizens have a say in those alternatives. Others are mute.
Some council members favor rebuilding the viaduct. Mayor Greg Nickels is irrevocably committed to the tunnel. The council's president, Nick Licata, is apparently against any vote of the people except a yes/no vote on the tunnel.
Restricting the viaduct alternatives to two, equally unsatisfactory, options — rebuilding an elevated structure in the existing right-of-way, or digging a tunnel — is unnecessarily narrow and destined to produce a foregone conclusion. The expert panel should look at other alternatives, including a bridge over Elliott Bay.
In a classic decision-making approach, the alternatives would be weighed against something like the following criteria:
• Costs should fall within "assured funding" limitations;
• No damage should be done to existing businesses (they are extremely sensitive to disruptions);
• Any "improvement" should open the waterfront.
The first criterion, in the absence of greater assured funding, would exclude the tunnel, while the third would exclude rebuilding the elevated highway structure; the second would preclude both a rebuild and the tunnel.
Evidently, neither of these two alternatives is "achievable" if the above criteria are to be met simultaneously. It is not sufficient for an alternative to meet only one or two. Thus, "achievability" would require relaxing, modifying, or removing one or more criteria.
The only way to comply with these criteria simultaneously is to include one or more additional alternatives. Truly viable alternatives have not been included and thoroughly explored. We are bogged down in a phony di-chotomy of "tunnel vs. rebuild." In the classic problem-solving scenario, the objective would be to find the least-cost alternative among those that are "achievable."
Many of us believe that there is but one way to meet all the criteria — a bridge over water. A new class of bridges, "cable-stayed," has surfaced in a variety of places to provide a potential solution. Cables are used not to suspend the bridge but to provide additional structural stability, where needed, to assure the bridge's integrity during high wind or seismic activity.
In Seattle, a cable-stayed bridge has been proposed for Highway 520 over Portage Bay. In France, the Millau viaduct has received much attention for its architectural elegance and imaginative engineering.
A more relevant example, though, is the bridge over the Gulf of Corinth in Greece. The Rion-Antirion bridge won the American Society of Civil Engineers' Outstanding Achievement Award last year. The cable-stayed design in Greece was selected precisely because of the long-span construction over water of a bridge that will be subject to significant seismic forces.
Because of foundation and seismic considerations, the bridge's cost in current dollars was near $1 billion. But that is still less than half the expense of the rebuild option for Seattle's waterfront. Why spend more than $2 billion to rebuild a drab elevated highway? Why spend more than $4 billion on a tunnel when an elegant, less-risky and less-costly alternative will meet the mayor's bottom line of opening the waterfront to development?
A bridge framing the Olympic Mountains would afford a magnificent platform for Seattle's magnificent setting and also would facilitate a separate process for the opening of the waterfront. To deal with the complexities, Seattle should host an international design competition, including especially those who have already built award-winning bridges.
In light of the partial collapse of Boston's "Big Dig" tunnel, Gov. Christine Gregoire's expert review panel seems destined to support rebuilding the existing viaduct. That would threaten to turn the project into another WPPSS-type financial debacle. The panel should evaluate all alternatives for the governor (and tax-paying citizens) to review and decide.
Though citizens are tired of politicians' failure to agree, they want a reasonable solution, one that does not involve needless spending of billions of scarce dollars.
Earl J. Bell is an emeritus professor in urban design and planning at the University of Washington. He can be reached at email@example.com
Copyright © 2006 The Seattle Times Company