The last stage of work on the northernmost portion of the big North Spokane Corridor freeway project is poised to get underway soon and will involve constructing an interchange at Parksmith Road.

The apparent low bidder for that work is Max J. Kuney Co., of Spokane, with a bid of about $6.9 million, the Washington state Department of Transportation says. It says it expects to award Kuney a contract soon so that work can begin this fall.

The Parksmith interchange project was made possible due to savings from the competitive construction bids that came in lower than anticipated for some earlier stages of the project, some of which are ongoing, says Al Gilson, a Spokane-based DOT spokesman.

Parksmith Road passes under the north-south freeway just east of the former Kaiser Aluminum Corp. Mead plant site, and it intersects Hawthorne Road and Market Street.

A bridge that allows the freeway to pass over the roadway there already has been constructed, also by Kuney. It was built as part of a separate contract to construct five bridges structures for the freeway to pass over or under other roads, including Shady Slope Road, Perry Street, Fairview Road, and Market.

Most of the preliminary earth-moving work needed to construct the interchange ramps also already has been completed as part of a previous project, the DOT says.

The Parksmith interchange project is scheduled to be completed during the middle of next year, the DOT says, and is intended to provide access from the north-south freeway to industrial and commercial sites located nearby.

Gilson says the project is being federally funded through the Transportation Infrastructure Generating Economic Recovery program. The DOT received about $35 million in grant funding from that program to construct about 3.7 miles of three southbound lanes of the north-south freeway between Francis Avenue and Farwell Road, which are on time to be completed in the first half of next year, Gilson says.

"Because of a favorable bidding climate, we had extra savings," Gilson says. "The grant was for work in the area, and the interchange is the last piece of work there."

Currently, both northbound and southbound traffic are using what ultimately will be the freeway's northbound lanes of travel, he says, and one lane is open in each direction on that side of the freeway.

Graham Construction & Management Inc., of Spokane, currently is working on the southbound lanes for that stretch under a $21.5 million contract.

Other ongoing projects in the Wandermere area include building a two-mile, four-lane section of the freeway and two bridges to connect U.S. 2 and the north-south freeway where it becomes U.S. 395. Graham Construction also is the contractor for that work under a separate $37.5 million contract that's being funded with proceeds from a 2003 Washington state gas-tax measure. Work on that contract is on schedule to wrap up next spring, Gilson says.

Graham also is working under a $42.8 million contract to lower the grade of U.S. 2 in the Wandermere area to allow for the new freeway interchange there, along with six bridges associated with the freeway and interchange. All of that work should wrap up later this fall, Gilson says.

Once the Parksmith interchange is finished next year, all of the north-south freeway project north of Francis will be completed, Gilson says, and 5.7 miles of the project's 10.5 miles between Wandermere and Interstate 90 will be open to traffic.

The next portion of the project that the DOT plans to tackle is the construction of a new and wider overpass for Francis where it will cross the north-south freeway.

The project is anticipated to cost about $38 million and will be state funded, Gilson says. He adds that work already is under way to design and engineer the structure.

That stretch of Francis currently passes over Burlington Northern Santa Fe railroad tracks via a four-lane overpass, but Gilson says that to accommodate both the north-south freeway and the tracks, a new span will have to be constructed there.

Savings from lower-than-expected contract bids for earlier stages of the project also are allowing that phase to advance sooner than had been anticipated, the DOT says.

So far, a total of just under $613 million in state, local, and federal funding has been spent or secured for the corridor project, and Gilson says that about $1.3 billion more—at current inflation rates—is needed to complete the remaining stretch from Francis to where it will connect with I-90 near the Thor-Freya interchange.

Funding for the next major phase of construction of the north-south freeway between Francis and the Spokane River hasn't yet been secured, except for the new Francis overpass, although Gilson says that a redesign of that section has reduced its cost by more than half, from an estimated $720 million to $328 million.

The DOT completed that redesign last year, and as part of that effort also split up construction of the north-south freeway between Francis and the river into separate stages to allow for construction to occur as funding is obtained for each.

The original design for that 3.5-mile section, created in 2000, called for the north-south freeway to be aligned in a grade lower than the BNSF railroad tracks that are to run parallel to the roadway, which for safety reasons would require six railroad bridges and large retaining walls along the road.

A redesign was called for in 2008 for a variety of reasons, including the inflation of construction costs, which had more than doubled since the project had been laid out, the DOT says.

The additional cost to build the extensive retaining walls and other construction materials that the old design called for rendered it inefficient. A limited availability of state and federal construction funding also meant that the project could be delayed for years until all of the needed funds were obtained, the DOT says.

"To reduce the cost and to enable staged construction, we did a redesign bringing the highway up to grade and putting the railroad track on the west side of the freeway," Gilson says. "That saved costs in a couple of ways ... now we can stage the construction."

The first stage of work between Francis and the river, following the construction of a new overpass at Francis, is a $69 million phase between Francis and Rowan Avenue that will include grading of the roadway, construction of related bridge and ramp structures, and the realignment of the railroad tracks.

A similar phase of work after that will extend between Rowan and Euclid Avenue and is expected to cost $70 million, the DOT says.

The next stage of work will be a $28 million interchange at Wellesley Avenue. Following the completion of that interchange, a phase is planned that will involve the final grading, paving, and the construction of related road structures and bridges is to extend between Wellesley and Francis at a cost of about $45 million.

The last step in the effort to extend the north-south freeway from Francis to the Spokane River will be the final grading and paving of the freeway from Wellesley to the river, and that work has been estimated to cost about $78 million.

The final push of the project is to connect the north-south freeway with I-90 near the Thor-Freya interchange, and that work is expected to cost almost $1 billion. No funding has yet been secured for that portion, and the DOT still is in the process of purchasing right-of-way for the extensive interchange work planned there.