Mercer Island Light Rail Station Design & Timeline

December 11, 2016 | by Erin Sirianni

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East headhouse at 80th Ave SE (looking west toward Seattle)

Last week, Sound Transit released the “completed final design” for Mercer Island’s light rail station, one of 10 new stations of Sound Transit’s East Link project, which expands its light rail system from downtown Seattle to Redmond.

Mercer Island’s station will be located at the center roadway of I-90 and will have two entrances (or “headhouses”) – one at 77th Ave SE and one at 80th Ave SE, near the Mercer Island Park-and-Ride lot.

West headhouse at 77th Ave SE (looking east)

Interior of the west headhouse, including elevator, stairs, and escalator to platform; art by Beliz Brother

The headhouses will include ticket vending machines, stairs, escalators, and elevators to the platform. The headhouses will also include artwork by Washington artist Beliz Brother.

Mercer Island Light Rail Station Platform

The platform will be 380 feet long, accommodating a four car-long train long. The platform will include canopy coverage and sound walls on either sides of the tracks to protect passengers from I-90 traffic noise.

For additional station design details, check out Sound Transit’s narrated PowerPoint presentation, as well as their updated station fact sheet.

Mercer Island Light Rail Station Timeline

Sound Transit’s East Link expansion project is now moving from its design phase to its construction phase, and work is currently underway to create full-time new “R8A” HOV lanes in the outer roadways of I-90, since the light rail will operate on the center lane bridge (currently the HOV lanes) from Seattle to Mercer Island.

Sound Transit expects that the existing I-90 center lane bridge will close and East Link construction will begin in June 2017. Here are additional upcoming dates on Sound Transit’s East Link development timeline:

  • Spring 2017 – Meet the Contractor Open House
  • June 2017 – I-90 center lane bridge closes; R8A (HOV) lanes open in outer roadways; Mercer Island station construction begins
  • 2016 – 2022 – Construction of East Link
  • 2022 – Testing and Pre-Operations
  • 2023 – Sound Transit’s East Link Light Rail and Mercer Island station open to public transit riders.

Bracing for construction

As mentioned above, construction to accommodate the addition of the R8A lanes is ongoing.  With drivers region-wide already experiencing delays (often during lane closures on weekends), many are concerned about traffic impacts when the center roadways will be permanently closed.

Further fueling our local traffic concerns, the Federal Highway Administration (FHWA) sent a letter to the City of Mercer Island in August 2016 determining that Single Occupancy Vehicles (SOVs) will no longer be allowed to use the R8A lanes when the center roadways are closed. Additionally, any SOVs departing from Mercer Island to Seattle in one of our most highly traveled westbound I-90 access points via Island Crest Way will no longer be permitted once light rail construction has started.

Mercer Island residents’ current use of the HOV lanes dates back to a 1976 agreement with transportation agencies when I-90 was expanded from five lanes to eight lanes across the Island.

After receiving this letter, the City commissioned a traffic impacts study that found that restricting SOV traffic from the Island Crest Way westbound on-ramp would cause significant delays and congestion on local roads and Mercer Island Town Center, as well as other negative impacts.

The City is in ongoing discussion with FHWA and Sound Transit about mobility issues resulting from construction of the light rail. You can learn more about the details and history of these discussions on the City’s website.

Getting ready for the ride

East Link Expansion Project

Fast forward to 2023, here’s what you can look forward to upon completion of East Link and the Mercer Island light rail station.

Sound Transit Link Light Rail System

  • Fast, frequent and reliable service 20 hours a day
  • Exclusive and semi-exclusive right-of-way for rail transit, separated from other traffic and congestion
  • East Link will connect to the Central Link line providing a one-seat ride (no transfers) from Overlake to the University of Washington via Bellevue, Mercer Island, downtown Seattle and Capitol Hill
  • Reliable connection to Sea-Tac Airport
  • Light rail trains are electric and do not emit harmful contaminants into the air
  • Development concentrated around light rail stations promotes walkable communities, which leads to improved public health and mobility
  • Light rail can carry crowds associated with fairs, sporting events, concerts, festivals, and other special events; trains can be lengthened based on demand.

Source: City of Mercer Island
Travel times (from Mercer Island Station)

  • International District/Chinatown = 10 minutes
  • University of Washington = 20 minutes
  • Bellevue Transit Center = 10 minutes
  • SeaTac Airport – 45 minutes (with transfer at International District Station)
  • Redmond Technology Center = 16 minutes

Source: Sound Transit

Learn more about ongoing developments related to Sound Transit’s East Link light rail expansion on the City of Mercer Island’s website.
Images credit: Sound Transit