The Washington State Department of Transportation awarded Skanska USA Civil the construction contract for the State Route 99 South Holgate Street to South King Street: Stage 2 project.

Skanska, based in Riverside, Calif., submitted the low bid of $114.6 million. The bid was 25 percent under the department's $152.6 million estimate.

“It’s official," Paula Hammond, Washington Transportation secretary, said in a Department of Transportation press release. "This summer, we’ll begin work to replace almost half of the aging and seismically vulnerable Alaskan Way Viaduct. This work is vital to public safety and will also ensure that traffic, goods and services continue to move across the region.”

Drivers won’t see any major construction closures or detours until early next year. State Route 99 will remain open to traffic during construction.

“We are thrilled to have Skanska on board,” Ron Paananen, the Department of Transportation's Alaskan Way Viaduct and Seawall Replacement Program administrator, said in the press release. “While most of the construction activities this year will not disrupt traffic, the public will notice a lot of work taking place in our construction areas near the sports stadiums.”

When complete in 2013, the southern mile of the Alaskan Way Viaduct will be replaced with a new side-by-side roadway that meets current earthquake standards, has wider lanes and improves mobility for people and goods in the Seattle area. The new State Route 99 also will feature new on and off-ramps near the stadiums that will replace the existing ramps to and from First Avenue South.

This stage of the project will put more than 600 people to work beginning this summer, according to the press release.

The new roadway will connect to any future replacement of the viaduct’s central waterfront section, including the proposed bored tunnel.

A newly painted orange column identifies the northern limits of this project.

A four-lane construction detour will connect the new section of State Route 99 to the existing viaduct just south of South King Street until the central waterfront section replacement is completed.

For more information on the Alaskan Way Viaduct and Seawall Replacement program, visit www.alaskanwayviaduct.org.