Mercer Stage 2 traffic switch complete
Stage 2 of Mercer East has begun and eastbound traffic on Mercer St. has been re-routed onto the new Mercer St. lanes north of the existing lanes. Three lanes of traffic are continuing eastbound on Mercer St. with access to the I-5 on-ramps and southbound Fairview Ave. N. 

• The far-right lane of eastbound Mercer St. is right-turn only at Dexter Ave. N.
• Access to Mercer St. from the south via Boren, Terry, and Westlake Avenues is concurrently closed at Republican St. 
• Right turns from Mercer St. onto Fairview Ave. N southbound are allowed; however, alternate routes should be used to reach Eastlake Ave. E and Capitol Hill (i.e. Dexter Ave. N to Republican St.) due to increased congestion on Mercer St.
• Left turns from Mercer St. onto Fairview Ave. N northbound are not being permitted during Stage 2.

Access to Northbound I-5 and SR 99 Detour Map
Access to Southbound I-5 and SR 99 Detour Map
Pedestrian Detour Map
Bicycle Detour Map

Canceling January 6 – 9 weekend closure of the I-5 on- and off-ramps at Mercer St.
A full weekend closure is tentatively rescheduled for the following weekend in January:

• January 13 – January 16

Closure hours are expected to be from Friday at 11:00 p.m. to Monday at 5:00 a.m. Please note this full weekend closure is weather dependant and subject to cancelation.

January 6 - 9: Next weekend closure of the I-5 on- and off-ramps
The next confirmed weekend closure of the I-5 on- and off-ramps at Mercer St. will be:

• January 6 – January 9

Closure hours are expected to be from Friday at 11:00 p.m. to Monday at 5:00 a.m. Please note this full weekend closure is weather dependant and subject to cancelation.

Access from I-5 Detour Map
Access to I-5 Detour Map

During weekend closures, the I-5 on-ramp at University St. will be concurrently closed to provide more efficient traffic flow around the closed Mercer St. exit lane. Fairview Ave. N will also be closed between Mercer St. and Valley St. and Mercer St. will be closed to through traffic between Westlake Ave. N and Fairview Ave. N. All detour routes will be clearly marked to support traffic flow around the closures.

Travelers are encouraged to carpool and use alternate modes of transportation. Transit information can be found at:

• King County Metro at www.kingcounty.gov/metro, or by calling 206-553-3000
• Sound Transit at www.soundtransit.org
• Seattle Streetcar at http://www.seattlestreetcar.org/
• Community Transit at www.commtrans.org

Access to businesses will be maintained during construction.

Mercer St. Stage 2 traffic switch begins Monday, January 9
On January 9, Stage 2 of the Mercer East Project will begin and eastbound traffic on Mercer St. will be re-routed onto the new Mercer St. lanes north of the existing lanes. Three lanes of traffic will continue eastbound on Mercer St. with access to the I-5 on-ramps and Fairview Ave. N.  This traffic shift will result in access restrictions to Mercer St. from the south, as access to Mercer St. via Boren, Terry, and Westlake Avenues will be concurrently closed at Republican St.  Alternate routes should be used to reach Eastlake Ave. E and Capitol Hill (i.e. Dexter Ave. N to Republican St.).

Read the full construction notice.

Mercer St. lane closures December 3 – 4
SDOT is advising travelers of intermittent lane closures on Mercer St. the weekend of December 3 - 4. Up to two lanes of Mercer St. will be closed to traffic to accommodate the decommissioning of a gas line on Mercer St. at 8th Ave. N. Closure hours will be 9:00 a.m. to 5:00 p.m.

Overnight single-lane closures on southbound I-5 on-ramp at Mercer St. scheduled for November 14 and 15
SDOT’s Mercer Corridor Project is announcing overnight single-lane closures on the southbound I-5 on-ramp at Mercer St. on Monday, November 14, and Tuesday, November 15. Closure hours are expected to be 7:00 p.m. to 5:00 a.m. These overnight single-lane closures accommodate storm drainage work on the southbound on-ramp to I-5 in preparation for the future two-way Mercer St.

Nighttime lane closures on Mercer St.  beginning October 31:
SDOT is announcing intermittent lane closures on Mercer St. beginning as early as Monday, October 31. Up to two lanes of Mercer St. at Boren Ave. N, 9th Ave. N and Westlake Ave. N will be intermittently closed overnight to accommodate gas line crossings of Mercer St. Two lanes will remain open to traffic at all times. Night work will be from 7:00 p.m. to 5:00 a.m., intermittently over the next two weeks.

9th Ave. N re-opening to traffic; Westlake Ave. N closure scheduled to begin late October:

9th Ave. N reopening to traffic
9th Ave. N between Aloha St. and Republican St. is tentatively scheduled to re-open to through traffic beginning October 25, weather permitting. During the closure, crews successfully:

• Replaced a nearly 100-year old sewer line between Aloha St. and Republican St.
• Updated all in-street utilities including undergrounding of electrical power and private communications lines and replacement of water mains, storm drainage lines, and gas lines.
• Rebuilt the roadway and sidewalks, installed irrigation lines and street light foundations in preparation for new landscaping and streetlights.

Please note the re-opened 9th Ave. N will be temporarily configured to one northbound lane and two southbound lanes while crews work to build the new Mercer St. lanes north of the existing lanes. In 2013, 9th Ave. N will be reconfigured into its permanent design, which includes a newly signalized intersection at 9th Ave. N and Westlake Ave. N.

Westlake Ave. N closed between Mercer St. and Valley St.
Westlake Ave. N between Mercer St. and Valley St. is tentatively scheduled to be closed to traffic beginning October 25 to allow underground utility installations and construction of new Mercer St. lanes crossing Westlake Ave. N. This closure allows crews to complete a “missing link” of the new Mercer St. roadway.

• Overnight on Monday, October 24, crews are scheduled to complete detour striping and temporary signal installation to accommodate implementing this closure. Please note this work is weather dependant.
• Traffic will be able to access businesses on Westlake Ave. N and right turns from northbound Westlake Ave. N onto Mercer St. will be permitted. This right turn lane will be signed for I-5 access only.
• Northbound Westlake Ave. N traffic from the city center will be detoured at Republican St. to 9th Ave. N. Southbound Westlake Ave. N traffic will also use 9th Ave. N.
• This configuration will be in place for several months while crews build new Mercer St. lanes across Westlake Ave. N.

• I-5 off-ramp to Mercer St: Right lane closure overnight on Tuesday, September 6, from 7:00 p.m. to 5:00 a.m.
• Westlake Ave. N lane shifts: One lane in each direction will be open between Aloha St. and 8th Ave. N as crews install underground electrical on the east side of the roadway. The west side of the adjacent parking lot will not be available for parking during this work.
• Roy St. west of 9th Ave. N: Night work continuing the week of September 6 between 7:00 p.m. and 6:00 a.m. followed by day work closing Roy St. beginning September 12.
• Roy St. east of Fairview Ave. N: Intermittent closures of this block of Roy St. to accommodate work near the I-5 off-ramp.
• Mercer St. lane closures near Terry Ave. N and Boren Ave. N: Up to three lanes closed overnight on Wednesday, September 7, from 7:00 p.m. to 5:00 a.m. to accommodate water main installation.

Upcoming construction activities in August, including night work on Mercer St. and Roy St. and ongoing 9th Ave. N roadwork

Beginning the week of August 22:

• Nighttime lane closures on Mercer St. at Westlake Ave. N, Terry Ave. N and Boren Ave. N

Beginning the week of August 29:

• Nighttime closure of Roy St. between 8th Ave. N and 9th Ave. N

Ongoing 9th Ave. N roadway restoration:

• Continued rebuilding and paving of 9th Ave. N between Aloha St. and Broad St. including tentatively scheduled night work the week of August 22.

Nighttime lane closures on Westlake Ave. N, Mercer St. and adjacent streets in early August
The Mercer Corridor Project is announcing temporary nighttime lane closures scheduled in early August, including:

• Beginning as early as Monday, August 1: Northbound Westlake Ave. N will be closed overnight between Mercer St. and Valley St. Northbound traffic, including King County Metro bus routes, will be detoured to Terry Ave. N from 7:00 p.m. to 5:00 a.m. for approximately one week. Southbound traffic will remain on Westlake Ave. N. For King County Metro bus information, please visit Metro Online at www.kingcounty.gov/metro and check the “Alerts Center.”
• Beginning as early as Monday, August 8: Nighttime lane closures will occur intermittently on Mercer St. at both Boren Ave. N and Terry Ave. N to accommodate water main installations lasting approximately three weeks. Up to three lanes of Mercer St. will be closed overnight, and Boren Ave. N and Terry Ave. N will have intermittent closures to through traffic between Republican St. and Mercer St. Work hours are expected to be 7:00 p.m. to 5:00 a.m.

July 22-25: Concurrent closure of Broad St. and I-5 on- and off-ramp closure at Mercer St.

While the Mercer St. on- and off-ramps are closed over the July 22 – 25 weekend, crews will take advantage of anticipated reduced traffic volumes on Broad St. to work in the intersection of Broad St. and 9th Ave. N for required storm drainage installations.

The closure will occur from Friday at 11:00 p.m. to Monday at 5:00 a.m. Crews may work up to 24-hours a day if required.

Travelers heading west on Valley St. toward Broad St. will be detoured to southbound Westlake Ave. N to Denny Way for access to the Seattle Center and downtown Seattle or northbound Westlake Ave. N to 8th Ave. N for access to lower Queen Anne and Dexter Ave. N.

Read the full construction notice.

Night work crossing Broad St. at 9th Ave. N

PSE crews will install gas utilities crossing Broad St. at 9th Ave. N beginning as early as July 5. Installation is expected to take one week and one lane of Broad St. will remain open accessing Roy St. and westbound Broad St.

Read the full construction notice.

9th Ave. N Construction Progress

Work to replace a nearly 100-year-old sewer line along 9th Ave. N between Aloha St. and Republican St. is now complete. The sewer bypass system at the intersection of 9th Ave. N and Aloha St. has been removed and the intersection of 9th Ave. N and Republican St. was re-opened to traffic in April.

What’s Next?

• Continued utility work: Installation of underground electrical and communications lines as well as storm drain, water, and gas lines on 9th Ave. N between Aloha St. and Broad St. Businesses will be converted to underground power and communications. Access to businesses will be maintained during construction.



• Complete roadway and sidewalk reconstruction on Westlake Ave. N north of Aloha St. and on 9th Ave. N between Aloha St. and Mercer St.: This work includes new roadway and sidewalks, new street lights, signage, and landscaping. 

Read the full construction notice outlining the scope and approximate time periods for construction activities on 9th Ave. N.

Work to replace a nearly 100-year-old sewer line along 9th Ave. N between Aloha St. and Republican St. is now complete. The sewer bypass system at the intersection of 9th Ave. N and Aloha St. has been removed and the intersection of 9th Ave. N and Republican St. is now open to traffic.

April 2011

Mercer Corridor Project: Upcoming full weekend closures of I-5 on- and off-ramps at Mercer Street scheduled for May
The Seattle Department of Transportation announces the upcoming confirmed weekend closures of the I-5 on- and off-ramps at Mercer Street. Full weekend closures will occur the following weekends:

• May 6 – May 9
• May 20 – May 23

Weekend closures will occur from Friday at 11:00 p.m. to Monday at 5:00 a.m. Read the press release

The I-5 on-ramp at University St. will be concurrently closed to provide more efficient traffic flow around the closed Mercer St. exit lane. Fairview Ave. N will also be closed between Mercer St. and Valley St. All detour routes will be clearly marked to support traffic flow around the closures.

A weekend closure is also tentatively scheduled for May 13 – May 16, pending final coordination with other major area projects.

Night Work on Mercer St. Near 9th Ave. N Will Continue Through April
Crews require additional nighttime lane closures on Mercer St. to complete underground utility work. Up to three lanes on Mercer St. will be closed overnight near the intersection of Mercer St. and 9th Ave. N. At least one lane will remain open. Weeknight work hours are from 7:00 p.m. to 5:00 a.m. through April, with intermittent single-lane closures in May if needed.

Open-Trench Sewer Installation and Roadway Rebuild on Westlake Ave. N North of Aloha St.
Crews will complete the remaining section of sewer line installation, followed by rebuilding a portion of Westlake between 8th Ave. N and Aloha St. Weekdays and weekend work, crews may work up to 24-hours a day if required for approximately six weeks.

Click here for 4/18/2011 Construction Notice

Detour Maps Now Available for the April 16th Weekend Closure of I-5 on- and off- ramps at Mercer Street
Detour maps are available for the previously announced weekend closures of the I-5 on- and off-ramps at Mercer Street as part of the Mercer Corridor Project.

Access from I-5 Detour Map
Access to I-5 Detour Map

First Weekend Closure of I-5 on- and off-ramps at Mercer St. Begins April 16
The Seattle Department of Transportation today announced the first full weekend closure of the I-5 on- and off-ramps at Mercer Street as part of the Mercer Corridor Project. The first closure is scheduled to begin at 1:00 a.m. on Saturday, April 16, through 1:00 a.m. on Monday, April 18.

During the closure of the I-5 on- and off-ramps at Mercer Street, SDOT and the Washington State Department of Transportation have determined that a concurrent closure of the I-5 on-ramp at University Street is necessary to improve safety and provide more efficient traffic flow around the closed Mercer Street exit lane. All detour routes will be clearly marked to support traffic flow around the closures. For this first weekend closure, times have been reduced from the anticipated standard hours of 11:00 p.m. on Friday to 5:00 a.m. on Monday in an effort to limit, as much as possible, the impact of this first closure. 

Read the full media release.

Upcoming Night Work at Mercer St. and 9th Ave. N
Nighttime work on Mercer St. and 9th Ave. N previously announced to begin as early as March 3 is now scheduled to begin on March 28 and will continue for up to three weeks.

Mercer St. will have up to three lanes closed overnight near the intersection of Mercer St. and 9th Ave. N. to accommodate the instillation of underground utilities across Mercer St. At least one lane will remain open to eastbound traffic on Mercer St. Night work hours are Monday-Friday, 7:00 p.m. to 5:00 a.m. for approximately three weeks.

March 2011

Upcoming Night Work at Mercer St. and 9th Ave. N
Mercer St. will have up to three lanes closed overnight near the intersection of Mercer St. and 9th Ave. N to accommodate the instillation of underground utilities across Mercer St. Eastbound traffic will be routed around the closure and will continue on Mercer St. Night work hours are weeknights, 7:00 p.m. to 5:00 a.m. for approximately two weeks.

Mercer St. to Republican St.: 9th Ave. N Sewer Installation Continues
Crews continue installing a new 30-inch diameter sewer line on 9th Ave. N. Nearby neighbors and businesses can expect:

• 9th Ave. N closed between Republican St. and Mercer St. during active work hours (local and emergency access allowed) and flaggers directing traffic as needed
• Access pits and heavy machinery
• Continued lane and sidewalk closures with appropriate traffic, bicycle and pedestrian detours
• Noise, dust, and vibration

Work Hours are weekdays and weekends and crews may work up to 24 hours per day if required. Work is anticipated to last six weeks.

Read the full construction notice outlining the scope and approximate time periods for construction activities on 9th Ave. N.

Adjacent Project Work: Dexter Ave. N. Paving Project
SDOT will begin repaving Dexter Ave. N between Fremont Ave. N and Roy St. on March 7, 2011. The project is being coordinated with the Mercer Corridor Project to consider joint traffic and detour impacts. For questions about the Dexter Ave. N Paving Project, please visit the project website at: www.seattle.gov/transportation/dexter_pave.htm or contact George Frost, Public Information Officer, at (206) 615-0786 or george.frost@seattle.gov.

Click here for 2/25/2011 Construction Notice

Updated Bicycle Routes, Pedestrian Access and Bus Stop Map
Please see the construction notice below for an updated map illustrating current bicycle routes, pedestrian access, and King County Metro bus stops in the project area. The following updates have been made since bicycle and pedestrian maps were distributed in November 2010:

• 9th Ave. N Sidewalk Closure
  To protect the safety of pedestrians and bicyclists, the east sidewalk of 9th Ave. N is now closed between Broad St. and Mercer St. Bicyclists and pedestrians are asked to use the west sidewalk of Westlake Ave. N to travel through this area.
• Terry Ave. N Closure
  Terry Ave. N is closed between Valley St. and Mercer St. to accommodate installation of upgraded utilities along the north side of Mercer St. and construction of new westbound Mercer St. lanes.
• King County Metro Temporary Bus Stops
  Temporary King County Metro bus stops are in use for the King County Metro Route 17 and Route 30, replacing bus stops that were closed during construction. For current transit information, please visit Metro Online at www.kingcounty.gov/metro and check the "Alerts Center."

Recommended Routes During Construction
While the eastbound Broad St. closure and 9th Ave. N lane restrictions are underway, the current construction notice shows maps of suggested routes based on current construction and traffic conditions.

Click Here for Detour Routes Construction Notice

The notice above includes maps of:

• Suggested bicycle routes
• Bus stop, sidewalk and crosswalk adjustments
• Routes for drivers from:
• Fremont to Eastlake
• Fremont to South Lake Union
• Capitol Hill to Queen Anne/Seattle Center
• Queen Anne/Seattle Center to I-5
• Queen Anne/Seattle Center to Eastlake

February 2011

Mercer St. to Republican St.: 9th Ave. N Sewer Installation Continues
Expect increased construction activity as crews continue installing a new 30-inch diameter sewer line on 9th Ave. N. Work Hours are weekdays and weekends and crews may work up to 24 hours per day if required.
Nearby neighbors and businesses can expect:

• 9th Ave. N closed between Republican St. and  Mercer St. during active work hours (local and emergency access allowed) and flaggers directing traffic as needed
• Access pits and heavy machinery
• Continued lane and sidewalk closures with appropriate traffic, bicycle and pedestrian detours
• Noise, dust, and vibration

Adjacent Project Work: Dexter Ave. N. Paving Project
SDOT will begin repaving Dexter Ave. N between Fremont Ave. N and Roy St. on March 7, 2011. The project is being coordinated with the Mercer Corridor Project to consider joint traffic and detour impacts. For questions about the Dexter Ave. N Paving Project, please visit the project website at: www.seattle.gov/transportation/dexter_pave.htm or contact George Frost, Public Information Officer, at (206) 615-0786 or george.frost@seattle.gov.

Aloha St. to Broad St.: 9th Ave. N Sewer Installation Continues
Expect increased construction activity to complete installation of a new 30-inch diameter sewer line. A temporary sewer bypass has been constructed to allow work on the existing sewer line. Nearby neighbors, businesses and travelers can expect:

• Flaggers directing traffic on 9th Ave. N between   Aloha St. and Broad St.
• Access pits and heavy machinery such as backhoes, front loaders and dump trucks
• Continued lane and sidewalk closures with appropriate traffic, bicycle and pedestrian detours
• Noise, dust, and vibration

Work Hours are weekdays and weekends and crews may work up to 24 hours per day if required. Work is anticipated to last two weeks.

Broad St. to Republican St.: Side Sewer Excavations
Excavation work will occur to connect side sewers to a temporary sewer bypass to support the mainline sewer replacement work. No interruption to sewer service is expected. Weekday work, 7:00 a.m. to 5:00 p.m. for approximately two weeks.

PSE Utility Work
Puget Sound Energy (PSE) is continuing independent utility work in the project area through the week of February 7. Questions about PSE work may be directed to Project Manager Tom Ling at 425-250-1544.

Read the full Construction Notice

January 2011

Upcoming Night Work
Night work will occur on Broad St. at 9th Ave. N for approximately one week. Westbound Broad St. will be reduced to one lane at the intersection of 9th Ave. N to accommodate the instillation of a temporary stormwater pipe needed for the sewer replacement. Westbound traffic will be routed around the closure and will continue on Broad St. Night work hours are typically between 7:00 p.m. and 6:00 a.m. Eastbound Broad St. remains closed to traffic between 5th Ave. N and 9th Ave. N.

Closure of Terry Ave. N from Valley St. to Mercer St.
As previously announced, Terry Ave. N will be closed between Valley St. and Mercer St. to accommodate installation of upgraded utilities along the north side of Mercer St. and construction of new westbound Mercer St. lanes. Closed to through traffic 24 hours a day, seven days a week, through 2011 as needed. The streetcar will continue to operate as usual on Terry Ave. N.

PSE Utility Work
Puget Sound Energy will be doing independent utility work in the project area including nighttime work crossing Mercer St. at Boren Ave. N and daytime work on Aloha St. between 8th Ave. N and 9th Ave. N. Questions about PSE work may be directed to Project Manager Tom Ling at 425-250-1544.Read the full Construction Notice.

Terry Ave. N Closure week of 1/10
As previously announced, intermittent work will continue on Terry Ave. N for the block between Valley St. and Mercer St. This section of Terry Ave. N will be intermittently closed during the day during the week of Monday, 1/10. Terry Ave. N is scheduled to be fully closed between Mercer St. and Valley St. later in January.

Upcoming Night Work Thursday, 1/6
Night work will occur on Broad St. near 9th Ave. N overnight on Thursday, 1/6. One westbound lane of Broad St. will be closed and traffic will be routed around the closure. Night work hours are typically between 7:00 p.m. and 6:00 a.m. Eastbound Broad St. remains closed to traffic between 5th Ave. N and 9th Ave. N.

Click here for 1/21/2011 Construction Notice

December 2010

Nighttime closures of Westlake Ave. N begin Monday 12/13
Night work is scheduled on Westlake Ave. N between Mercer St. and Valley St. on the following dates:

• Monday 12/13 – Thursday 12/16
• Monday 12/20 – Thursday 12/23 (if needed)

Northbound traffic on Westlake Ave. N will be closed at Mercer St. and detoured to Terry Ave. N. Southbound Westlake Ave. N will be open with one southbound traffic lane. These closures are necessary to accommodate utility work under the Seattle Streetcar tracks. Night work hours are 7:00 p.m. to 5:00 a.m.

Terry Ave. N closures week of 12/20
Terry Ave. N will be closed to traffic from Monday 12/20 – Thursday 12/23 to accommodate utility work. Note that Terry Ave. N will remain open during nighttime closures of Westlake Ave. N .

November 2010

Mercer Corridor Project night work, including Mercer St. lane closures beginning Monday, 11/15
Night work is scheduled to begin as early as Monday, 11/15, to accommodate the installation of a sewer bypass and dewatering system needed for the 9th Ave. N sewer replacement and associated roadway work.
Temporary, intermittent night work will occur in the following areas on weekdays between Monday, 11/15, and Tuesday, 11/23. Night work hours are typically between 7:00 p.m. and 6:00 a.m.

• Mercer St.: Nighttime closures of two to three lanes of Mercer St. between Dexter Ave. N and Westlake Ave. N.
• Westlake Ave. N: Nighttime restrictions of Westlake Ave. N to one lane in each direction in areas between Aloha St. and Mercer St.
• Valley St: Nighttime restrictions of Valley Ave. N to one lane in each direction between Terry Ave. N and Westlake Ave. N.
• Broad St.: Nighttime restrictions of westbound Broad St. to single lane near 9th Ave. N.
• Terry Ave. N: Nighttime closures of Terry Ave. N between Mercer St. and Valley St.

October 2010

9th Ave. N and eastbound Broad St. closures in place
Closures of eastbound Broad St. and of 9th Ave. N to through traffic began on Tuesday, October 12. Overnight on Monday, October 11, crews completed installation of temporary signals and detour striping to accommodate implementation of these closures.

September 2010

Traffic Alerts:
 9/24/2010 Construction Notice
 9/17/2010 Construction Notice
 9/15/2010 Construction Notice