Planning a third wave of Seattle LRT 04 Jul 2013
Peter Kenyon, TunnelTalk
Seattle has begun the process of planning for a third wave of transit projects (ST3) that includes a light rail link between Ballard in the north-west of the city, and Downtown.
Transit study area

Transit study area

Engineering and planning consultant Parsons Brinckerhoff is jointly engaged by transportation agency Sound Transit and the City of Seattle to take eight possible route options for the 6-9 mile light rail link and narrow them down to four for a Level 2 analysis this fall. The contract with PB is worth US$2.8 million.
Of the eight options (see panel on the right), four include significant tunnelling elements, including a possible underwater crossing of the ship canal at Salmon Bay. A Sound Transit spokesman told TunnelTalk: "Based on conceptual engineering estimates Option 2 would include 4 miles (6.4km) of tunnels, Option 5, 2.9 miles (3.2km), Option 6, 2.5 miles (4km) and Option 3, 1.6 miles (2.6km)."
The eight potential routes, drawn up by a technical team from an initial list of 200, have been identified as part of the Ballard-Downtown High Capacity Transit study, which will help inform updates to the City of Seattle's Transit Master Plan and Sound Transit's Long Range Plan (LRP). The plans identify priorities for potential future transit expansions.
Sound Transit Board member and Seattle Mayor Mike McGinn, said: "Our updated Transit Master Plan, adopted unanimously by the City Council last year, identifies a Downtown to Ballard transit line as a top priority."
The alternatives include tunnels under the ship canal and Queen Anne, at-grade routes using the Fremont Bridge, and elevated routes crossing the ship canal on new bridges. Preliminary cost estimates range from $500 million to $3 billion.
Option 2 includes 6.4km of tunnels

Option 2 includes 6.4km of tunnels

The Sound Transit spokesman said: "With the level one analysis complete, the team will measure the eight alignments against the study criteria in order to take four corridors to a level two analysis that includes more refined analysis. That will be complete this fall."
He added: "No funding has been identified beyond these early studies to update the LRP. At a high level, the Ballard to Downtown High Capacity Transit study is one of nine corridors the agency is examining as it updates its Long Range Plan (LRP). The LRP is essentially a long-term menu of mass transit priorities for the Board to pick and choose from for potential future ballot measures. The Ballard corridor, like all the others, is not funded and the Board has not identified any of them for a new ballot measure in the future. This is all very preliminary planning work. The Board has said they want us to do this work in time to put a ballot measure to voters in 2016 - but it's important to note a decision has not been made whether they want a vote in 2016. They just want to be ready."
Although nine transit corridors are being investigated for a possible 2016 ballot measure, only the Ballard-Downtown and South Corridor are currently being analyzed.
The Ballard-Downtown route, if selected for possible funding, would connect with the existing Central Link to Downtown Seattle, as well as the planned East Link to Bellevue across Lake Washington - a project that is in final design in advance of a scheduled construction procurement process due to start 2014-15. It would also link with the under-construction University Link, as well as the soon-to-begin Northgate extension. In May, Sound Transit awarded a US$440 million contract to a JV of Jay Dee/Collucio/Michaels for construction of the 5.5km of twin tube tunnel required for the Northgate extension.
References
Seattle Northgate LRT Link bid result - TunnelTalk, May 2013
Seattle pushes on with LRT extensions - TunnelTalk, August 2012
Seattle selects East Link route - TunnelTalk, August 2011
Build out plans for Seattle LRT - TunnelTalk, July 2010

           

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