Last updated 5/21/2013
New Traffic Configuration Now in Effect
The new configuration of SR 99 and Mercer St. is now in effect and travelers can expect the following changes to the corridor:
- Mercer St. reduced to two eastbound lanes between 4th Ave. N and 9th Ave. N.
- Local access maintained at Taylor Ave. N.
- The sidewalk on the north side of Mercer St. is closed between 5th Ave. N and Dexter Ave. N. The sidewalk on the south side of Mercer St. will remain open.
- Broad St. open to two-way traffic.
- SR 99 traffic shifted to the west side of the roadway between Valley and Harrison streets. Two lanes of SR 99 in each direction will remain open.
- The northbound SR 99 off-ramp to Mercer St. is permanently closed. A new signalized intersection at Republican St. and Dexter Ave. N is available for northbound SR 99 traffic to reach South Lake Union.
- Due to the re-opening of Broad St. to two-way traffic, left turns from eastbound and westbound Mercer St. onto 9th Ave. N will be restricted in order to facilitate traffic flow on Mercer St. Travelers heading north towards Westlake and Fremont should use Dexter Ave. N to reach their destinations.
Lane reductions on Mercer St. will continue throughout the West Phase of the Mercer Corridor Project, which is anticipated to be completed in mid-2015. Construction of this $95 million project will take approximately 2.5 years.
When completed, the West Phase of the Mercer Corridor Project will provide a direct connection from I-5 and the new SR 99 Tunnel to Uptown, the Seattle Center, and neighborhoods to the west. In addition to widening Mercer St. for two-way traffic, the project includes improved pedestrian connections, a bike path between Dexter and Fifth avenues N, replacement of the SR 99 bridge over Mercer St., and signal and channelization modifications to make Mercer and Roy streets two-way through the Uptown area.
Click here to view detour maps.
Upcoming lane restrictions on northbound 9th Ave. beginning Wednesday, May 8
SDOT advises travelers of upcoming lane restrictions on northbound 9th Ave. N between just south of Aloha St. to 8th Ave. N beginning Wednesday, May 8. During this time, 9th Ave. N will be reduced to a single northbound lane as crews work on underground utilities along the curb lane for approximately three weeks. One lane of northbound traffic will remain open at all times.
Westlake Ave. N fully closed to traffic for Stage 4 construction beginning Wednesday, April 3
Westlake Ave. N will be fully closed to through traffic between Mercer and Aloha streets beginning the morning of April 3, as crews begin underground utility installations and roadway demolition and restoration.
- Local access to Westlake Ave. N businesses between Mercer and Valley streets will be maintained. No through travel onto Valley St. will be permitted.
- This configuration will be in place for approximately four months while crews complete utility improvements and rebuild the roadway on Westlake Ave. N.
Routes for vehicles during Stage 4 construction
Routes for Pedestrians during Stage 4 construction