The state released its cost estimates for replacement of the aging Alaskan Way Viaduct this morning, and tunnel options come in as the most expensive: $3.5 billion for one and $2.7 billion for the other.

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The state released its cost estimates for replacement of the aging Alaskan Way Viaduct this morning, and tunnel options come in as the most expensive: $3.5 billion for one and $2.7 billion for the other.

The least expensive replacements would be surface options ranging in cost from $800 million to $900 million.

The cost estimates will be presented later today to a group of viaduct stakeholders: industry, environmental and neighborhood leaders who have been meeting for months to evaluate the eight viaduct options.

Other options, retrofitting the existing viaduct and building a bridge over Elliott Bay, were considered and discarded.

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The state will narrow the options to two or three in December. Gov. Christine Gregoire, King County Executive Ron Sims and Seattle Mayor Greg Nickels will then choose a preferred option by the end of the year.

Already the state has evaluated each option for everything from travel times to seismic safety.

The cost estimates released today include price ranges for five categories of improvements that go along with each of the eight options: improvements to Interstate 5, transit, surface streets, policies and management, and how to encourage alternatives to driving alone.

The Washington Legislature appropriated $2.8 billion for replacing the viaduct, but the state has already spent or committed more than $1 billion, leaving $1.5 to $1.8 billion for replacing the mile-long central waterfront portion of the viaduct. The cost of another elevated viaduct can be done with the available funds, as can the surface options, under the state’s estimate. The tunnels couldn’t.

The most-expensive option released today was a deep-bored tunnel at $3.5 billion, far above the money allocated by the Legislature. But Ron Paananen, who is leading the viaduct effort with the state Department of Transportation, said that doesn’t mean it’s off the table.

“We’re not making that determination,” he said. “It’s too early to answer the question if there’s enough money.” He said the eventual winner of the viaduct sweepstakes likely will be a hybrid of all eight finalists.

Paananen also released a document that lists 56 other funding options for the viaduct replacement, everything from federal congestion mitigation funds to systemwide tolling of state roads, to money from the King County Ferry District and even naming rights to a new viaduct.

What the cost estimates didn’t include are other options on the table, such as changing the downtown carpool ramps so all vehicles could use the Cherry Street exit, adding another lane to northbound Interstate 5, adding more streetcars downtown and in Seattle neighborhoods, greatly expanding transit, and requiring that businesses subsidize transit passes.

The DOT also announced low long each viaduct option would take to build.

The eight options and their costs and building time are:

• A four-lane boulevard along Alaskan Way, including with multiple stoplights. : $800 million. Five years, to build, if the existing viaduct is closed; 5.5 if it is partially open.

• A four-lane boulevard along Alaskan Way. This option would create about 80 feet of open space along the waterfront: $800 million. Also five years if viaduct is closed; 5.5 years if partially open.

• A six-lane Alaskan Way-Western Avenue couplet. The two northbound lanes would be on Western and the southbound lanes on Alaskan Way. It would create 110 feet of open space on the waterfront: $900 million. Five and a half years if viaduct is closed or partially open.

• A four-lane elevated viaduct, with the lanes side by side, not stacked. This would be similar to the existing viaduct and would retain the views: $1.6 billion. 6.5 years if viaduct is closed; 8.5 years if partially open.

• Aa four-lane elevated viaduct, proposed by Frank Chopp, speaker of the state House of Representatives, that would be covered by a park, with buildings underneath. : $2.2 billion. 7 years if viaduct is closed; 8.5 years if it is partially open. This price doesn’t include the buildings underneath the roadway, just the road, a park on top and some kind of covering on the sides.

• A four-lane bored bypass tunnel that would start near Qwest Field and go under Western Avenue and Post Alley. The only offramp would be at King Street. This tunnel would be 100 feet deep in places and would go under the Burlington-Northern railroad tracks. It would also go under the Battery Street Tunnel: $3.5 billion. 9.5 years whether the viaduct is open or closed.

• A cut-and-cover tunnel along the central waterfront. It would be four lanes and emerge onto an elevated roadway at Stewart Street and a surface street by the Pike Place Market. It also calls for the I-5 HOT lane: $2.7 billion. 6.5 years if viaduct is closed; 8 years if it is open.

• A four-lane lidded trench, with two lanes in each direction. There would be openings in the cover to ventilate the roadway. It also calls for signals on streets north of the Battery Street tunnel: $1.9 billion. 6 years if viaduct is closed; 6.5 years if it is opened.

Annual operating costs for the various options range from $3 million to $10 million.

Gregoire wants to start tearing down the viaduct in 2012.

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