$1.3B project aims to make I-90 user-friendly

In 1905, a Ford traveled over Snoqualmie Pass, the first car to go from Ellensburg to Seattle. The trip took three days.

Today, more than a century later, the state is embarking on a major project to straighten a 15-mile stretch of the roadway that carries, on average, 27,000 cars and trucks each day. On weekends that can rise to 50,000.

According to the state Department of Transportation (DOT), 35 million tons of freight cargo, valued at $500 billion, crosses I-90 every year. The department estimates that by 2029, more than 51,000 vehicles will use I-90 daily, including more than 19,000 trucks.

Called the Snoqualmie Pass east-corridor program, the first phase of the project, estimated to cost $545 million, will add a lane each way for five miles between Hyak and Keechelus Lake and will double the size of the snow shed covering the roadway to help guard against the kinds of avalanches that have frequently closed the highway.

It's expected to take seven years to finish the first five miles of the project, and the state has committed to leaving two lanes open during peak travel time.

The main aims of the project, according to DOT, are to reduce the number of curves, lessen the need for road closures because of avalanche-control work, reduce rock and debris falling onto the road, replace damaged concrete, provide another lane for expected increases in traffic and double the size of the snow shed in the westbound lanes on the east side of the pass.

It's being funded by the 9.5-cent gas-tax increase approved by the Legislature in 2005. Eventually, the state hopes to build a six-lane freeway from Hyak all the way to Easton, if funding can be found.

The overall 15-mile project is estimated to cost about $1.3 billion.

Seventy percent of the I-90 closures in a typical winter are in the five-mile stretch being improved, said Brian White, an assistant regional administrator with the DOT.

Accidents, avalanches, rockslides and extreme weather close the pass for an average of 120 hours each year.

The 500-foot snow shed now covers just two lanes, the original width of the old Highway 10 before it was upgraded and became an interstate. The new 1,000-foot snow shed, estimated to cost $64 million, will cover all six lanes of traffic, White said.

The DOT hopes to begin construction next summer and have it completed in the summer of 2015. Work can only be done between April and October, when the snow has melted.

Ancient thoroughfare

The existing road itself is 50 years old, said White, and showing its age.

The route through what is now Snoqualmie Pass was originally a Native American trail, said Jason Smith, the environmental manager with the project. The year the Model T went through, establishing the corridor as the main route to the Pacific ports from the eastern side of the state, is the same year DOT was formed.

In 1915, the DOT officially dedicated the east-west route as the Snoqualmie Pass Highway and declared it the state's first passable road between Eastern and Western Washington, even though it was closed six months of the year.

In the 1920s the road was paved, and during the 1950s it was expanded from two to four lanes. It wasn't until 1931 that the highway was open year-round; in 1937, the Snoqualmie Pass ski area was established.

It was called Highway 10, the Sunset Highway, until it was brought up to interstate standards and became I-90.

Wildlife concerns

Part of the east-corridor project also will look at fish and wildlife crossings, and the state has been studying the migratory patterns of animals.

The state said it considered, but rejected, a proposal that it build a tunnel through Snoqualmie Pass, largely because of cost.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com