Gov. Chris Gregoire signed a bill today, May 12, that commits $2.8 billion in state money to help build a tunnel under the Seattle waterfront to replace the 56-year-old Alaskan Way Viaduct.

Gregoire signed the bill today at 2 p.m. at the downtown Seattle Waterfront Aquarium.

She posted the following on her Twitter page: "The tunnel bill is signed! Thanks to mayor, county executive, port and legislature for support. New jobs, waterfront, and transpo capacity coming soon."

The tunnel and associated elements of the plan will cost more than $4 billion and Seattle and King County are responsible for the rest. The mile-long elevated section of Highway 99 carries a little more than 100,000 vehicles a day, according to the state department of transportation.

Kristy Van Ness (Laing), communications manager for the Alaskan Way Viaduct and Seawall Replacement Program, said the $4 billion price tag also includes a new waterfront surface street, transit investments, and downtown waterfront and city street improvements. The bored tunnel portion is estimated to cost $1.9 billion, she said.

Gregoire is scheduled to travel to Tacoma Wednesday, May 13, to sign the $7.5 billion state transportation budget.

Other bills she will sign in the near future include a bill that will dedicate $620 million for the county to start building pontoons for a new Highway 520 floating bridge.