Sound Transit completes construction of elevated light rail trackway between Seattle and Tukwila

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Sound Transit contractors today hoisted the last of 2,457 concrete segments into place to finish almost five miles of elevated light rail trackway between South Seattle and Tukwila.

“Over the last two years people have watched the elevated tracks go up along I-5 and SR-518. Their on-schedule, on-budget completion is a major accomplishment,” said Sound Transit Boardmember and King County Councilmember Julia Patterson. “People are ready to start riding light rail in 2009. Light rail will offer fast, congestion-free commutes no matter how bad traffic gets.”

“These elevated light rail tracks will offer Sound Transit’s riders a nice view of the rising congestion on I-5 and other surface streets as they zip past, arriving at work or home on time,” said Sound Transit Boardmember Larry Phillips, chair of the agency’s Central Link Oversight Committee and a King County Councilmember. “We know that by 2040 our population will have increased more than 40 percent. Our electric light rail trains will keep our growing population moving while taking cars of the road and addressing climate change.”

PCL Construction Services is building the stretch of light rail trackway from Boeing Access Road to the Tukwila light rail station at International Boulevard and S. 154th Street in Tukwila. With the concrete elevated structure now complete, PCL will continue installing rails and working on the nearly complete light rail station in Tukwila.

About 85 percent of the Tukwila trackway is elevated, supported by 190 columns rising as high as 70 feet. The contractor employed an innovative construction method never before seen in our region, using a 385-foot-long gantry truss that “walked” from column to column along the alignment. The gantry lifted each 35-ton pre-cast concrete segment into place and supported the segments while PCL crews fastened them together with steel cables. Once a span between two columns was completed, the gantry moved on to the top of the next column.

PCL also achieved major successes using pre-cast concrete segments to build “balanced cantilever” bridges crossing I-5, a major railroad yard, busy freight arterial roads and the Duwamish River. Once the bridges were completed, the gantry walked across them continuing northward.

Construction of the 15.6-mile light rail line between downtown Seattle and the airport is more than 75 percent complete and moving forward on schedule and within budget toward its 2009 opening. The line between downtown and Tukwila will open for passengers in summer 2009, with free shuttles to the airport until the December 2009 opening of the 1.7-mile extension that will provide direct airport service.

Watching the completion of the final elevated span, Phillips, Patterson and Sound Transit Boardmember and Edmonds City Councilmember Richard Marin emphasized the importance of light rail protecting the local and global environment. They noted that the transportation sector makes up 50 percent of the region’s carbon footprint.

On Wednesday, the American Public Transportation Association released a study on greenhouse gases that showed public transportation is a key weapon in combating pollution and global climate change. One commuter who normally drives alone can reduce their carbon footprint by 10 percent by simply switching to public transportation. If one person in a two-car household gives up using the second car entirely, he or she can reduce the household’s carbon footprint by 30 percent. More information on the study is available at 
“Nationally, light rail has demonstrated strong success encouraging more people to use transit. In addition to taking cars off roads, light rail systems across the country have promoted the creation of walkable, livable communities where people are less dependent on automobiles,” said Marin said.

The regional Roads & Transit ballot measure that is on the November 2007 ballot includes 50 additional miles of light rail, with extensions from the University of Washington to north of Lynnwood, from downtown Seattle east to Bellevue and Redmond, and south from the airport to Tacoma. By 2030, the package’s Sound Transit 2 investments would expand the agency’s daily ridership to more than 350,000 and reduce annual vehicle miles traveled by 330 million. More information on the Sound Transit 2 plan is available at

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Sound Transit’s regional network of express buses, commuter rail, light rail and transit facilities connects communities in King, Pierce and Snohomish counties.