The Seattle Department of Transportation (SDOT) advises travelers of the upcoming nighttime closure of northbound SR 99 and Mercer Street between Fifth Avenue N and Ninth Avenue N the evening of Tuesday, September 17 in addition to a nighttime closure of Mercer Street the evening of Wednesday, September 18 for work associated with the West Phase of the Mercer Corridor Project.
Northbound SR 99 and Mercer Street Closure: Evening of Tuesday, September 17
Beginning Tuesday evening through Wednesday morning, Mercer Corridor Project crews will set girders necessary for rebuilding the east half of the SR 99 bridge over Mercer Street. Northbound SR 99 and Mercer Street will be fully closed to traffic beginning Tuesday, September 17 at 10:00 p.m. through Wednesday, September 18 at 5:30 a.m. During the closure:
- Northbound SR 99 will be fully closed between the southern end of the Battery Street Tunnel and Valley Street. Traffic traveling through Seattle via SR 99 will be directed to I-5 south of Seattle at E Marginal Way and Spokane Street. More information about alternate routes during construction may be found at: http://www.seattle.gov/transportation/mercercorridor.htm.
- Mercer Street will be fully closed to traffic between Fifth Avenue N and Ninth Avenue N. Traffic heading east towards I-5 will be detoured to Harrison and Broad streets at Fifth Avenue N and will reconnect to Mercer Street at Ninth Avenue N to continue east. Travelers heading east from Dexter Avenue N should take Republican Street to northbound Ninth Avenue N to re-connect with Mercer Street.
- No pedestrian access will be allowed on Mercer Street between Fifth Avenue N and Dexter Avenue N during the closure. Pedestrians will need to use the sidewalk on the north side of Broad Street to cross SR 99.
- Southbound SR 99, Broad Street, and the I-5 on- and off-ramps at Mercer Street will remain open during the work.
Additional Mercer Street Closure: Evening of Wednesday, September 18
Mercer Street will be fully closed to traffic on Wednesday, September 18 at 10:00 p.m. through Thursday, September 19 at 5:30 a.m. while crews erect false work necessary for the new eastern half of the SR 99 bridge over Mercer Street. During the closure:
- Mercer Street will be fully closed to traffic between Fifth Avenue N and Dexter Avenue N. Traffic heading east towards I-5 will be detoured to Harrison and Broad streets at Fifth Avenue N and will reconnect to Mercer Street at Ninth Avenue N to continue east.
- No pedestrian access will be allowed on Mercer Street between Fifth Avenue N and Dexter Avenue N during the closure. Pedestrians will need to use the sidewalk on the north side of Broad Street to cross SR 99.
- Westbound Mercer Street, Broad Street, and the I-5 on- and off-ramps at Mercer Street will remain open during the work.
Early warning signs will be available in advance of the northbound SR 99 and Mercer Street lane restrictions. Travelers can expect significant traffic and delays and should plan ahead and use alternate routes.
Media inquiries should be directed to the SDOT media Hotline at 206-684-3151.