During a weekend closure of the I-5 on- and off-ramps at Mercer St. in May, crews were able to complete a number of tasks including installation of storm lines on the ramps, electrical wire pulling underneath Mercer St., and pouring almost 175’ of concrete to pave the old lanes of Mercer St.

The weekend of May 11 – 14, crews paved almost 175’ of the old lanes of Mercer St.

Seattle City Light crews cutover power on Mercer St. east of Fairview Ave. N

In April, crews completed important tasks such as installation of utility lines and an underground air sparging system, while continuing to pave the old lanes of Mercer St.

Crews placing an underground air sparging system at at Westlake Ave. N & Mercer St.

Placing concrete on the south side of Mercer St.

In March, crews have been running communication and utility lines under the old lanes of Mercer St. in coordination with Seattle City Light. The roadway is being updated in preparation for two-way traffic on Mercer St., anticipated later this summer or early fall.

Electrical duct banking, fiber, and gas lines at Boren Ave. N and Mercer St.

LED lighting installed around bench foundations on the new Mercer St.

Crews have been hard at work in February installing underground utilities in the old Mercer St. roadway including, water, electrical and communication lines. Due to the large volume of work, crews have been working both day and night shifts at times to complete the necessary work.

Installation of underground utilities in the old Mercer St. roadway

Crews also completed the roadway and north sidewalks on Roy St. between 9th Ave. N and Dexter Ave. N.

The newly paved Roy St. roadway

The first car to drive on the new lanes of Mercer St.

Mercer St. at Fairview Ave. N
The Mercer Corridor Project met a major milestone on Sunday, January 29th as the “Mercer Switch” began and eastbound traffic on Mercer St. shifted to the new lanes north of the existing lanes. The old Mercer St.has now been shut down and the project team is working diligently to replace ageing utilities and rebuild the old roadway in preparation for two-way Mercer St. in late 2012.

New Mercer St. lanes north of the existing lanes.
Crews are busy finalizing the new Mercer St. roadway in preparation for the “Mercer Switch” when traffic is re-routed onto the new Mercer St. lanes north of the existing lanes.

Westlake Ave. N closure
Crews have been hard at work installing underground utilities and constructing the new Mercer St. lanes crossing Westlake Ave. N. This closure allows crews to complete a “missing link” of the new Mercer St. roadway.

Newly re-opened 9th Ave. N

9th Ave. N between Aloha St. and Republican St. re-opened to through traffic beginning October 25. 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.

New pavement on 9th Ave. N

Grading and paving is nearing completion on 9th Ave. N between Aloha St. and Broad St.  Crews are currently rebuilding sidewalks in preparation for the roadway to re-open to traffic and pedestrians in mid-October.

Crews excavating the roadway in preparation for new pavement on 9th Ave. N.

Pavement removed on 9th Ave. N.


Crews preparing to pave the roadway on 9th Ave. N.

Crews are busy at work beginning to re-pave 9th Ave. N. The lanes on the west side of 9th Ave. N just north of Aloha St. to Broad St. have been removed and crews have begun grading the roadway in preparation for paving new lanes. Once complete, crews will switch construction to the east side of the roadway and repeat the process of grinding and paving.

Crews installing updated storm drainage utilities in the intersection of Broad St. and 9th Ave. N during the July 22 – July 25  I-5 on- and off-ramp weekend closure

Crews working in the intersection of Mercer St. and Fairview Ave N. during the July 22- July 25 I-5 on- and off-ramp weekend closure

Crews were busy the month of July with two full-weekend closures of the I-5 on- and off-ramps at Mercer St. The July 22 – July 25 weekend closure included a concurrent closure of Broad St. between Westlake Ave. N and 9th Ave. N. During this closure, crews took advantage of anticipated reduced traffic volumes on Broad St. to perform storm drain work in the intersection of Broad St. and 9th Ave. N.

Crews working on a new storm drain system in the intersection of Mercer St. and Fairview Ave N. during the June 17- June 20 I-5 on- and off-ramp weekend closure.



Duct banking for a 115KV transmission line on Fairview Ave. N

Crews were busy installing utilities in the intersection of Mercer St. and Fairview Ave. N, including storm drainage systems, water main pipes, and underground electrical lines during the June 17- June 20 weekend closure of the I-5 on- and off-ramps.

The May 6 – May 9 closure included storm drain installation along the I-5 on- and off-ramps.



Crews temporarily patch work completed on the I-5 on- and off-ramps.

Two full weekend closures of the I-5 on- and off-ramps occurred in May. Crews began trenching and utility installations including storm drain lines along the I-5 Mercer St. on- and off-ramps.

Newly restored intersection at 9th Ave. N and Republican St.





Sewer installation near the Courtyard Marriott Hotel

Crews have completed work to replace a nearly 100-year old sewer line at the intersection of 9th Ave. N and Republican St. The intersection has now been re-opened to traffic. Northward, crews are working to install a new 30-inch sewer pipe on Westlake Ave N between 8th Ave. N and Aloha St. near the Courtyard Marriott Hotel.

Installation of a new 30-inch sewer pipe continues along 9th Ave. N between Aloha St. and Republican St. Crews are working on the south end of 9th Ave. N. and are installing Seattle City Light vaults at 9th Ave N and Boren Ave. N. to connect utilities in the area.

Instillation of a new 30-inch sewer pipe continues along 9th Ave. N between Aloha St. and Republican St. To minimize surface impacts, much of the construction activity will continue to occur below ground, using a pipe reaming machine to bore through the soil and place the new pipe.  

Crews began installation of a new 30-inch sewer line and associated pipe reaming on 9th Ave. N between Aloha St. and Mercer St. Additional work continues including installation of Seattle City Light ductbanks on the north side of Mercer St. between Fairview Ave. N and Boren Ave. N. and site preparation of the area just south of Broad St. between 9th Ave. N and Dexter Ave. N.

SDOT’s contractor continued excavation and shoring activities for the drill pits necessary for the 9th Ave. N sewer replacement. Nighttime work occurred on Mercer St. between Dexter Ave. N and Fairview Ave. N to accommodate the installation of the sewer bypass system. Additional temporary bus stops were added to the project area for Metro Routes #17 and #30.

SDOT’s contractor began excavation and shoring activities for the drill pits necessary for the 9th Ave. N sewer replacement.  Two pits are located on 9th Ave. N – one between Mercer St. and Broad St. and one at Republican St.  The contractor has been working nights to install a sewer bypass system as well as a dewatering system.  Additional work includes installation of Seattle City Light ductbanks on the north side of Mercer Street between Fairview Ave. N and Boren Ave N. and site preparation of the area just south of Broad St. between 9th Ave. N and Dexter Ave. N.

Traffic control impacting two major streets was implemented early this month to accommodate the start of construction activities. 9th Ave. N was closed between Mercer St. and Broad St., with lane restrictions between Aloha St. and Broad St. and between Harrison St. and Mercer St. Additionally, eastbound Broad St. was closed between 5th Ave. N and 9th Ave. N to accommodate site preparation and regarding activities at Broad St. between 9th Ave. N and Dexter Ave. N. King County Metro completed work to remove overhead trolley lines on Fairview Ave. and the bus routes on this street were successfully converted to diesel service for the duration of Mercer construction. The overhead trolley line removal will allow for more efficient construction within the work zone on Fairview Ave. N between Republican St. and Aloha St. Trolley lines will be re-installed and energized at the end of the project. The preload materials installed on the north side of Mercer St. during the building demolition phase was removed and relocated, and Seattle City Light vault installation work began at Mercer St. and Fairview Ave. N.

SDOT held a groundbreaking ceremony on September 8, 2010. Some of the attendees were: U.S. Secretary of Transportation Ray LaHood, Governor Christine Gregoire, WSDOT Secretary Paula Hammond, Seattle Mayor Mike McGinn, U.S. Senator Patty Murray, and U.S. Representative Jim McDermott.  Work in progress includes:  tree removal on Westlake Ave. N, 9th Ave. N and Broad St.; preconstruction survey work and settlement monitoring installation; closure of Boren Ave. N between Mercer St. and Valley St. to accommodate work to relocate preload material.

The demolition contractor passed final inspection on their demolition and site preparation work and the project team is now preparing for the start of major construction. Notice to proceed was issued August 9, 2010 for the east phase of the Mercer Corridor Project.

The demolition contractor completed final inspection for demolition and site preparation work that began in March 2010. SDOT and its contractor, Gary Merlino Construction Company, are preparing schedules and work plans for roadway construction.

SDOT awarded the construction contract to local contractor Gary Merlino Construction Company. Demolition crews continue to remove vacant buildings between Mercer St. and Valley St. to make room for future roadway construction. 

Demolition crews continued to remove vacant buildings between Mercer St. and Valley St. to make room for future roadway construction.  A total of eight buildings will be demolished as part of this work.

Preload material is being installed north of Mercer St. between Fairview Ave. N and Terry Ave. N to help consolidate the foundation of the future roadway to avoid settling and cracking. The preload material will remain for several months and will then be removed.

Demolition work continues north of Mercer ST. to prepare for future construction.

Demolition crews are removing vacant buildings between Mercer Street and Valley Street to make room for future roadway construction.

The first stage of the Mercer Corridor Project has started; work includes the demolition of a building at 1104 Mercer Street.