Road Building

County and state agencies set to transform Salmon Creek interchange.

Clark County and the Washington Department of Transportation have been struggling to unravel the traffic snarl in the Salmon Creek area for more than a decade.

The Salmon Creek Interchange project, which began in July, seeks to alleviate traffic in the vicinity by constructing a new overpass over the highway junction at 139th Street.

First Independent Bank, and president of the Hazel Dell/Salmon Creek Business Association, called the opening of the WSU Vancouver campus and Legacy Salmon Creek Medical Center a "boon" for the area, but said the traffic infrastructure was "not adequate for the development that followed." 

Chuck Holt, sales manager for Ariel Truss Co., located near N.W. 139th Street in Vancouver, was even more blunt. "Traffic is brutal," Holt said.

The Salmon Creek Interchange Project proposes to change all that.

The Challenges   

Both the county and WSDOT are concerned with minimizing construction impact on local businesses and traffic. According to Clark County Public Works project engineer Jean Singer, the two agencies were developing phasing plans that would give contractors guidelines about what to do first. Also, she said, they were trying to be flexible with area businesses with unique needs.

During construction contractors will meet weekly with business owners to garner feedback on the impact of construction. One example of meeting unique needs could be found at the Salmon Creek Fred Meyer store, with the county giving the Portland-based chain the funds to do the necessary frontage alterations themselves.

According to state and county planners involved in the effort, there are unique technical, logistical and environmental challenges associated with this project. Singer said they incorporated new land use and growth forecasts into the design process, as well as accommodating high groundwater levels and a plan to protect adjacent wetlands.

WSDOT Vancouver Area Engineer Leon Winger said that much of the soil in the project area was considered poor quality, adding that during earthquakes, it would tend to liquefy. To meet earthquake design standards, WSDOT must install stone columns under ramp approaches and create large walls by vibrating a giant probe 50 to 65 feet into the ground, then, as it is pulled out, filling the void with rock.

Bridge columns will require similar modifications with shafts 100 to 130 feet deep, 8 to 10 feet in diameter, made of concrete and steel. For the main 139th Street bridge, there are five shafts per pier, with eight or nine piers total, according to Winger.

The Plan               

The SCIP is one of the largest public works projects in Clark County history, with a total estimated cost of $133 million. According to WSDOT Region Design Engineer Rick Keniston, the road construction effort is unique because of the close partnership between WSDOT and the County Public Works Department.

"We've worked as one team, sharing resources," Keniston said.

The overall vision is to modify the existing 134th Street freeway interchange, as well as provide a second interchange one mile north at 139th Street, with the county performing surrounding road improvements and WSDOT performing the interstate work.

Major construction for the SCIP won't start until next spring, though dust is flying on one piece of the project – the grading for a new Park & Ride lot near N.E. 139th Street at 10th Avenue (the existing location will be converted into storm water treatment ponds). Coffman Excavation of Oregon City is taking advantage of the dry weather to complete this $1.2 million grading project. Singer said the county has already performed signal optimization on 134th Street.

Singer said road improvements around the interchange, estimated at $12 million to $14 million, will begin next spring. Those include two widening projects, realigning Tenney Road and building a round-about.

WSDOT expects to commence its portion of the project next summer. Winger said their first priority is to build a new temporary on-ramp to northbound I-5 off 139th Street. Then they will close the existing on-ramp at 134th Street, realign I-205 northbound to the west (to accommodate vertical clearance issues), then build the 139th Street bridge. They will also add lanes to I-5 between 139th and 179th streets.

The entire project is slated to be complete by early 2014.

During construction the project is expected to create 600 jobs, including workers directly involved with the construction work and positions indirectly created through the spending of workers' wages.

The Future           

When the project is complete, said Jeff Mize, Public Works' Public Information Outreach Manager, motorists will have access to two east-west corridors, reducing congestion and improving safety. Jonathan Avery, chief administrative officer of Legacy Salmon Creek Medical Center, said that the project will also improve emergency vehicle access to the medical center.

Business owners, too, are excited by the project.

"It's been a long time in coming," said Ron Wilson, who owns several commercial properties along Hwy. 99 between 129th and 134th streets. "These improvements have removed the construction moratorium, which was disastrous for property owners and businesses that wanted to develop in the area. I'm looking forward to completion of the new interchange."

"It's fair to say that this project will provide a huge long-term boost to an area that has tremendous economic potential but has been hampered by inadequate infrastructure, Mize said.