The state and Seattle officials today said they would move forward this summer with work on portions of the Alaskan Way Viaduct project...

OLYMPIA — The state and Seattle officials today said they would move forward this summer with work on portions of the Alaskan Way Viaduct project, but gave themselves two more years to figure out a final replacement solution.

The agreement comes in the wake of Tuesday’s vote that rejected both a tunnel and a new elevated highway along the waterfront.

The plan unveiled today in a noon press conference at Gov. Christine Gregoire’s office also includes work to shore up parts of the aging viaduct and increase inspections of the structure.

Engineers have said the viaduct could collapse in a major earthquake.

Gregoire said she wants the state to start dismantling the viaduct by 2012.

“I am determined to take it down before it falls down,” she said.

Cost of the repairs and upgrades to start this summer is estimated at $915 million.

The work includes:

• Stabilizing viaduct footings near Washington Street.

• Building a new interchange near Qwest and Safeco fields to help trucks and commuters to move between the waterfront and south downtown.

• Relocating two electrical transmission lines and five feeder lines from the viaduct to Western and First avenues.

• Adding lighting, fire suppression, seismic upgrades and ventilation to the Battery Street tunnel.

• Strengthening steel structures from Lenora Street to the Battery Street Tunnel.

• Replacing the highway from Holgate Street to Royal Brougham Way.

The announcement was made by Gregoire, Seattle Mayor Greg Nickels and King County Executive Ron Sims.

Gregoire has supported replacing the viaduct with a $2.8 billion elevated highway. Nickels backed a four-lane, $3.4 billion tunnel.

Neither option won a majority of votes in Tuesday’s election.

Gregoire said the work announced today would be required regardless of which replacement option is finally chosen.

“We want all of us to come together,” she said. “We’re on one page today, moving forward.”

Gregoire said a final decision on how to replace the central portion of the viaduct must be made within two years, before the state’s next biennium budget is approved.

Nickels said he is open to alternatives.

“I will not be advocating a tunnel. I will not be advocating any particular solution,” he said.