Reality for viaduct may be retrofit

A new element has been added to the discussion of what to do about the earthquake-crippled Alaskan Way Viaduct. That element is reality. It's a grim reality, made so by the abysmal failure of Referendum 51 and the close but convincing success of Initiative 776. Both dashed hopes for state funding for any grand transportation improvements.

There isn't much hope, either, for a regional approach. Earlier this year, the Legislature authorized King, Pierce and Snohomish counties to create a regional package of transportation projects, including local-option taxes to pay for it. The three county executives offered a proposal, but it depended on funds generated by R-51. It's unlikely that elected officials in three counties agree on one key regional project. Elected officials are loath to ask their constituents to tax themselves for a project by which they are not directly served.

In a perfect world, leaders in the three counties could agree that the region's most pressing transportation problem is the Alaskan Way Viaduct. Each day, 110,000 vehicles move through the narrow Seattle corridor on this elevated stretch of State Route 99. It carries about 25 percent of the north-south traffic through the city, sharing the regional north-south demand with I-5 and I-405.

The viaduct differs from almost all of the region's other transportation project demands in that it presents a clear and present -- and major -- threat to safety. The structure likely will collapse in the next major earthquake. There's an estimated 1-in-20 chance that will happen in the next 10 years. The result would be nothing short of catastrophic -- in the potential loss of life on the structure and in its impact on the region's transportation capacity. Only the 520 bridge presents a similar risk of collapse in an earthquake of 7.5 magnitude or more. The viaduct is the more pressing project because of the damage already inflicted on it by last year's 6.8 magnitude Nisqually quake, the risk that its multi-layered design could "pancake" in the next temblor and the fact that it's located in the midst of the region's most densely populated urban area. Regardless of the clear stake the region has in the viaduct, the dawning reality is that Seattle and King County may have to go it alone to fix the problem. The state has insufficient money to meet routine transportation needs and voters rejected an increase in state funding; federal funding for road projects has all but dried up and the waiting list is long for what's left.

That means a realistic approach to costs. The Department of Transportation says a private group proposed in 1994 to rebuild the Mercer corridor and tunnel along Alaskan Way for $1.4 billion. George Kargianis, a member of the State Transportation Commission, told the Post-Intelligencer in March 2001 that replacing the viaduct could cost about $400 million, while retrofitting it to withstand earthquakes would cost $460 million.

Before the failure of R-51, estimates for a viaduct project ran as high as $15.9 billion for a tunnel and traffic improvements in a plan that would run from Spokane Street to Mercer and the Seattle Center. Since voters turned down R-51, the highest replacement estimates being discussed include: rebuilding the structure essentially as it is for $2.9 billion or a bit wider for $3.3 billion, and a tunnel route for $4.7 billion. No estimate has yet been made for Mayor Greg Nickels' ground-level six-lane "boulevard" approach.

Doing nothing and risking the disaster of the viaduct's collapse is the worst alternative.

The second-worst is to spend billions of dollars to rebuild the same noisy wall between downtown Seattle and its waterfront. If the viaduct is to be replaced, it should be replaced with a below-grade structure. It would be the first grand mistake of the new century to miss the opportunity to reunite these two essential parts of the city.

Ron Kasprisin, instructor at the University of Washington's College of Architecture and Urban Planning, asked his students to come up with proposals for reconnecting Seattle with its waterfront. He asked them to assume that the viaduct will be removed and replaced with a tunnel and/or surface lanes because rebuilding the same sort of structure would be "too much of a compromise" that "would not be in the best interest of the city. It's fascinating to see what happens when you take the viaduct away." The students' 11 proposals were unveiled Friday.

But if money must be the dominant driver, perhaps the best alternative will be to retrofit the existing structure to at least survive a major earthquake while we search for the ultimate solution and a way to pay for it.

In September, City Councilman Nick Licata organized a meeting with state Department of Transportation Secretary Doug McDonald and two engineers from Imbsen & Associates, a California firm specializing in bridge retrofitting. At the meeting, Dr. Roy Imbsen said that a retrofit would work as an interim solution for as long as 25 years. Imbsen estimated that the retrofit could be done for under $500 million and could even be done in stages, as money became available.

Before any serious consideration of viaduct alternatives can be undertaken, the retrofit idea should be thoroughly reviewed by city and state transportation staff and outside professionals.

Whatever the chosen solution or its cost, Seattle and King County need to find a way to pay for it, likely through a combination of local-option taxes and tolling.

Then the city and county should turn their attention to finding a way to fix the 520 bridge. If large state or regional contributions somehow materialize for either project, then so much the better. But it's foolhardy to wait until nature leaves us no choice.

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