• Project

SR 520 I-5 Express Lanes Connection Project

Project overview

The SR 520/I-5 Express Lanes Connection Project will create a dedicated reversible transit and carpool connection between SR 520 and the I-5 Express Lanes, along with a reversible transit/carpool ramp at the I-5/Mercer Street interchange.

August 2021 - 2024
Project status
$68 million
Project hotline

What to expect

The southbound Interstate 5 off-ramp to Mercer Street, and the express lanes exit to Mercer St., will fully close beginning at 4 a.m. Saturday, Feb. 11 through 4 a.m. Monday, Feb. 13. Crews will be working on a new retaining wall. Detours will be in place.

The off-ramp will reopen from 6pm-8pm on Saturday, Feb. 11 to allow for traffic to access an event at Climate Pledge Arena. The ramp will close for the remainder of the weekend following that.

The westbound SR 520 off-ramp to southbound I-5 is reduced to one lane through at least February 2023. 

Any schedule changes to upcoming closures will be communicated here and on the SR 520 Construction Corner webpage.

Area map of SR 520/I-5 Express Lanes Connection Project in Seattle.