Graham Construction & Management Inc., of Spokane, has won a $42.8 million contract to lower the grade of U.S. 2 in the vicinity of a planned interchange for the North Spokane Corridor freeway and to construct six bridges associated with the interchange.

The interchange will be located a short distance north of Farwell Road. The planned new freeway and U.S. 2 will intersect there diagonally as the North Spokane Corridor swings west to meet U.S. 395, about a mile to the northwest near Wandermere Golf Course.

The contract with Graham was awarded by the Washington state Department of Transportation, which plans eventually to construct what traditionally has been known as the north-south freeway along a 10.2-mile stretch between U.S. 395 near Wandermere and Interstate 90 near the Thor-Freya exit in East Spokane. The overall project currently is expected to cost $3.3 billion.

DOT regional spokesman Al Gilson says a start date for the work Graham will do hasn't been determined yet, but is expected to take 620 working days once it gets started. He says it's not clear how much of the earthmoving work for the lowering project can be done in the winter months.

A portion of the project will entail lowering the grade of an about 1.4-mile stretch of U.S. 2 north of Farwell Road, says Larry Larson, a DOT project engineer.

The highway will be lowered as much as 30 feet in that area to accommodate the planned interchange's bridges. The new freeway, as well as some on-ramps, off-ramps, and associated roadways, will cross over U.S. 2 there.

Gilson says the DOT tries to keep the grade of its freeway projects at 5 percent or less, and tries to strike a balance between lowering and filling in project areas.

The other main part of Graham's contract will include constructing six bridges that will be part of the interchange. Some of that work, says Larson, could begin during the time the stretch of U.S. 2 is being lowered.

One of the bridges will be 980 feet long and will be constructed of steel because it will be built with a significant curve, he says. It will carry southbound traffic from U.S. 2 to the southbound lanes of the new freeway, and will cross above U.S. 2, the new freeway, and Farwell Road.

The other five bridges all will be smaller, generally about 200 feet long, and made of concrete. They will be used for on-and off-ramps for the interchange, Larson says.

The project also entails repaving the lowered road, constructing more than 100,000 square feet of retaining walls, installing guardrails, and building a 30-foot-wide culvert under U.S. 2 for Peone Creek, also known as Deadman Creek, which is located near the northeast end of the stretch of U.S. 2 that will be lowered as part of the project.

Larson says that during the project, two northbound lanes of U.S. 2 will remain open at all times, but there might be only one southbound lane open at times, with Market Street used as a southbound alternative.