Overnight work at Shorewood Drive: Oct. 22 and 23

Publish Date

Beginning as early as Tuesday, Oct. 22, the first traction power substation (TPSS) will arrive on Mercer Island and will be installed at Shorewood Dr. and I-90. TPSS units provide electricity to the overhead wires which power light rail vehicles.To safely complete this work, the Island Crest Way eastbound on-ramp and two eastbound I-90 right lanes will close overnight as crews lift the TPSS unit into place. Traffic will also be reduced to one-lane alternating direction along Shorewood Dr. to accommodate the crane and placement.

Due to the size of the delivery, the truck carrying the TPSS unit will be led by pilot vehicles as it travels to the delivery site. Drivers may notice slower traffic along I-90 and off-ramps during this time. Temporary light plants and generators may be used and noise from the crane placing the unit may be noticeable. Nighttime work will be in accordance with the Temporary Construction Noise Exception Request, approved by the City of Mercer Island. Noise mitigation measures will be in place to minimize impacts and lighting will be directed downward away from nearby homes to the greatest extent possible.


Traction power substation (TPSS) delivery at Shorewood Drive and I-90 (see map)


  • Island Crest Way eastbound on-ramp: Tuesday, Oct. 22, 10 p.m. – 5 a.m. Wednesday, Oct. 23.
  • Eastbound I-90 two right lanes: Tuesday, Oct. 22, 11 p.m. – 5 a.m. Wednesday, Oct. 23.
  • Shorewood Dr. overpass: Tuesday, Oct. 22, 9 a.m. – 1 p.m. Wednesday, Oct. 23.


Eastbound I-90 at Shorewood Drive


  • The Island Crest Way eastbound on-ramp will be closed Tuesday, Oct. 22 from 10 p.m. – 5 a.m. Wednesday, Oct. 23. Two right I-90 eastbound lanes will close just east of Shorewood Drive on Tuesday, Oct. 22, from 11 p.m. – 5 a.m. Wednesday, Oct. 23.
  • The Shorewood Drive overpass will be reduced to one lane alternating direction Tuesday, Oct. 22, from 9 a.m. - 1 p.m. Wednesday, Oct. 23.
  • Crews will use a crane to lift the TPSS unit from I-90 and install it at Shorewood Drive.
  • Construction light plants and generators may be noticeable.
  • Traffic control will be in place. Drivers should follow signage and direction of flaggers to safely reach their destination.  
  • Plan ahead, leave early and allow extra time to reach your destination. 
  • Due to inclement weather or unforeseen issues, dates and times are subject to change.
Map of overnight work at eastbound I-90 at Shorewood Drive.