ALERT: Westbound SR 520 off-ramp to northbound I-5 and E. Roanoke St. closed most weeknights

View our Portage Bay piledriving schedule: Week of Nov. 2 – 8 (last updated Oct. 30, 2026)

SR 520/I-5 Express Lanes Connection Project

Despite the clouds, Seattle is looking pretty spectacular in this overhead view of the SR 520/I-5 interchange with Lake Union and downtown in the background. Crews recently wrapped improvements at the interchange, including a flyover ramp that will eventually connect SR 520 to the I-5 Express Lanes when the Portage Bay Bridge and Roanoke Lid Project is complete.

Completed in 2025, the SR 520/I-5 Express Lanes Connection Project created 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.

I-5 Express Lanes Connection Project Webpage

SR 520/I-5 Express Lanes Connection Project

Construction photos

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