April 8–15: Prepare for closures and detours on SR 99 and Seventh Avenue North.

If you travel using SR 99, closures and detours are happening this week. Plan ahead and prepare for changes to your route!

Why is this work happening?

Crews are conducting their first regular inspection of the new SR 99 tunnel. They are also installing railing on the shoulders of the NB SR 99 off-ramp to Alaskan Way and downtown.

Meanwhile, crews working on the North Surface Streets Project will be closing three blocks of Seventh Avenue North (formerly Aurora Avenue North) this weekend for paving and installing temporary lighting.

Here’s what you can expect:

Weekdays: Monday, April 8 – Friday, April 12

Northbound SR 99 off-ramp to Alaskan Way and downtown will be closed 9 PM – 5 AM, Monday – Friday nights (4/8 – 4/12). There will be no exits northbound on SR 99 between the West Seattle Bridge and the north end of the SR 99 tunnel. Drivers looking to reach SODO, the waterfront or the south end of downtown should use East Marginal Way, 1st Ave, or other surface streets.

Seventh Avenue North will be closed 9 PM – 5 AM, Monday, 4/8 – Thursday, 4/11. The northbound lane is closed Tuesday and Thursday nights, and the southbound lane is closed Monday and Wednesday nights. The northbound detour will be Dexter Avenue North and Harrison Street. Southbound detour will be Harrison Street and Sixth Avenue North.

Weekend: Friday, April 12 – Monday, April 15

Southbound SR 99 tunnel will be closed 11 PM Friday, 4/12 – 8 AM Saturday, 4/13. All southbound SR 99 traffic approaching the tunnel will have to leave the highway at Harrison Street.

Northbound Seventh Avenue North will be closed 9 PM Friday, 4/12 – 5 AM Monday, 4/15. The detour for drivers to reach the northbound SR 99 on-ramp will be Dexter Avenue North and Harrison Street.

Project area map


Routes 5, 26, 28, and RapidRide E Line will be rerouted off of Aurora Ave N between Harrison St and Denny Way from Monday, 4/8 at 8 PM to Tuesday, 4/9 at 5 AM. Southbound stops are changing. Visit Metro’s website for more information.

Routes 120, 125, and RapidRide C Line are rerouted off of SR 99 due to the construction on the NB off-ramp at S Dearborn St. The reroute will occur from 4/8 – 4/12 from 8 PM-5 AM. More information on reroutes for routes 120 and RapidRide C Line is available on King County Metro’s website,  and information on route 125 is available here.

Want more information?

Want traffic news as it happens? Follow SDOT Traffic on Twitter for Seattle traffic updates and WSDOT’s traffic Twitter account for Puget Sound highway traffic conditions. More information on these closures is available on WSDOT’s website.