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23rd Avenue Corridor Improvements Project

Updated April 26, 2016

Phase 1 Construction | Current Schedule | Background | Outreach | Materials | Cost | Contact Us

Translatedproject materials available below

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  • ትግርኛ /Tigrinya
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Upcoming construction activities

  • Crews will work at the intersection of E Union St and 23rd Ave from 6 AM on Saturday to 11 PM on Sunday on April 30 – May 1 for storm drain and signal work. Travel through the intersection will be detoured, but local access will be provided to nearby destinations.
  • Temporary driveway closures are occurring as crews continue paving and doing sidewalk work in zones A and B. Please use caution and pay attention to sidewalk closures and pedestrian detours. If you have any questions about the work happening near you, please call the project hotline at 206-727-8857.
  • On Monday, March 14, crews opened 23rd Ave to two-way traffic between E Yesler Way and E Cherry St, allowing better access to businesses, homes, and community organizations in the area. Neighbors should still expect construction between S Jackson St and E Cherry St (Zone A) until later this spring, however travel in both directions will be maintained throughout the remaining work. Northbound 23rd Ave will be closed with detours to Martin Luther King Jr Way from E Cherry to E Union St through summer.
  • Crews are making a concerted effort to address community concerns about the construction zone and signage.
    • Crews moved construction materials and some equipment to an off-site staging yard to improve the cleanliness of the construction area. This off-site location will also be used for contractor parking, to make sure more street parking is available for business customers and local residents.
    • Crews are now using orange and white partitions on site to help more clearly mark pedestrian detours. 

Businesses are open during construction

  • Businesses on 23rd Ave are open and accessible during construction. Show your support by staying in the neighborhood to eat, shop, and play!

  • On February 22, Mayor Murray announced the creation of a business stabilization fund to assist micro businesses affected by 23rd Ave construction. Go here for more information. The deadline to submit an application for the stabilization fund is Friday, April 29 at 5 PM.

Phase 1 Construction underway
Travelers in the Central Area can expect major traffic changes now that work is underway to replace the 100-year-old water main and rebuild a safer 23rd Ave. Phase 1 construction, from S Jackson St to E John St, started in June 2015 and should be complete by early 2017. In February 2016, crews finished replacing nearly 1.5 miles of the old water main. Construction is also underway on the adjacent Central Area Neighborhood Greenway

We divided the project area into three work zones. Here's what's happening now:

  • Crews reopened 23rd Ave to two-way traffic in Zone A, from S Jackson St to E Cherry St, on March 14. However, neighbors should expect still expect construction in Zone A until later this spring as crews will continue rebuilding the street.
  • In Zone B, from E Cherry St to E Union St, crews are rebuilding the street. A full northbound closure with detour to Martin Luther King Jr Way is in effect.
  • In Zone C, from E Union St to E John St, crews have finished their early work to replace the water main. Crews will return to rebuild the street and sidewalks in late spring or summer. Drivers can expect bumps and areas of uneven pavement in Zone C until construction is complete in this area in early 2017.

During construction, we encourage commuters and neighbors to use the signed detour routes or other arterials and avoid cutting through neighborhood streets.

Questions during construction? 
Call the hotline: 206-727-8857



What traffic impacts can I expect?
Crews have made good progress rebuilding 23rd Ave since construction began in June 2015. Crews are rebuilding the street in Zone A and extended this work into Zone B on November 30, 2015. Work to replace the 100-year-old water main is complete in all three construction zones. Crews will return to Zone C to rebuild the street and sidewalks in late spring or summer.

The project is on schedule for completion in early 2017. However, the timing and phasing of the northbound detour changed from original plans and included some overlap between Zone A and Zone B. This overlap was needed to keep the overall project on schedule as a result of construction challenges we encountered in Zone A with the planned locations for the new trolley poles. Read  the FAQs for more information.

  • Zone A - S Jackson St to E Cherry St: June 2015 – spring 2016; Zone A reopened to two-way traffic on March 14, however, construction activities are ongoing
  • Zone B - E Cherry St to E Union St: November 30, 2015 – summer 2016; current detour (see map); early utility work completed
  • Zone C - E Union St to E John St: spring or summer 2016 – early 2017; early utility work completed
  • While the construction detour is in place in a specific zone, you can expect the following changes within that zone:

Traffic closures and changes:

  • Full northbound closure of 23rd Ave with a detour to Martin Luther King Jr Way
  • Southbound 23rd Ave traffic reduced to one lane
  • Longer travel times in the area
  • Metro bus reroutes and stop relocations
  • Restricted access to residential side streets from 23rd Ave
  • Partial and/or full weekend closures of key intersections

Typical work schedule:

  • Monday through Friday between 7 AM and 5 PM
  • Periodic evening and weekend work

Other temporary construction impacts:

  • Noise, dust and vibration
  • Heavy equipment and trucks traveling and staging
  • How to use the detour

Northbound traffic within the active construction zone will be detoured east to Martin Luther King Jr Way. To access a home or business mid-zone, drivers will need to use Martin Luther King Jr Way (or another nearby arterial) to travel northbound and turn onto an east-west street at the end of a zone – E Yesler Way, E Cherry, E Union or E Madison/John streets – to then go southbound on 23rd Ave. Use the detour map at right to determine how to access a business or residence mid-zone on 23rd Ave.

We expect the first few weeks of detours in each zone to be a challenge as you adapt to the new routes. We appreciate your patience as we make adjustments to keep traffic and people moving – please plan for extra time as you travel through the corridor.

How to access your home or business during construction

Pedestrian access to your home or business entrance will be maintained. Crews can close driveways temporarily, but the Community Liaison will notify businesses and residents prior to driveway work. For businesses with a driveway of 20 feet or wider, crews may be able to work on half of the driveway at a time to maintain access.

King County Metro bus detours and stop changes

During construction, there will be long-term bus reroutes and stop relocations.

To get the latest information about your route and any changes, visit Metro's Service Advisories, check for posted Rider Alerts at your bus stop, sign up for Transit Alerts for your route, or call Metro at 206-553-3000. 

Why is northbound 23rd Ave closed?

To ensure the safety of pedestrians and drivers, as well as to allow enough space for crews to safely complete their work in a timely manner, northbound traffic in the active work zone will be detoured to Martin Luther King Jr Way. Southbound traffic will be maintained, though reduced to one lane at most times.

23rd Ave is a narrow street. Maintaining two-way traffic requires 22 feet, or 11-foot-wide lanes, at a minimum. Construction activities and equipment require approximately 30 feet of the roadway. The graphic below illustrates why there is not enough space in the road to accommodate more than one lane of traffic during construction

Click to view larger

Keeping your neighborhood safe and moving during construction

To balance the various needs of everyone who lives, works, plays and goes to school on and around 23rd Ave, we have identified some tools to help manage traffic and keep people safe on the neighborhood’s streets. These include:


  • Signal timing modifications to keep traffic moving
  • Left-turn restrictions to minimize traffic backups and improve traffic flow
  • Signage, including detour information
  • An adjacent neighborhood greenway to provide a safe place for people to walk and bike


  • Uniformed police officers (UPOs) and flaggers on site at the start of major traffic changes
  • Traffic speed and volume analysis
  • Speed trailers where warranted, based on analysis

How will the contractor rebuild the street?

The construction work to rebuild 23rd Avenue will consist of four main activity types:

  • Removals
    • Remove select street trees
    • Remove the existing roadway
  • Utility work
    • Replace the water main
    • Install drainage pipes
  • Rebuilding
    • Repave the roadway
    • Install sidewalks and new curb ramps
  • Final restoration work and clean up
    • Plant street trees
    • Restripe and cleanup

Your favorite businesses and organizations will be open during construction
In addition to safety and mobility, we want to ensure the local businesses and places you visit regularly remain accessible during construction.
To help local businesses stay accessible and minimize some of the construction impacts they may experience, the City will:
Minimize impact to customer access

  • Divide the construction work into three zones to limit the amount of construction time in front of any one business
  • Ensure the contractor provides continual pedestrian and vehicle access for customers
  • Place “Businesses Are Open” signs to encourage patronage during construction
  • Limit the number and duration of interruptions to driveway access
  • Keep the project area as tidy as possible throughout construction

Provide communication tools to businesses

  • Provide businesses with project information cards for front counters and/or customized maps or materials to support their individual marketing efforts
  • Have a community liaison available on-site or by phone 24 hours a day
  • Provide advance notice about construction activities, including email updates and door-to-door flyers
  • Host monthly drop-in sessions to discuss construction updates and any community concerns
  • Maintain a website with updated construction information

The City has additional resources available for businesses and organizations affected by construction; see our project materials section below. If you are a local business/organization and would like more information, please contact the Office of Economic Development directly at 206-684-8090.

On February 22, Mayor Murray announced the creation of a business stabilization fund to assist micro businesses affected by 23rd Ave construction. For more information, please visit the Office of Economic Development's website.

Construction contact information

Construction can be difficult. If you experience any issues or have questions during construction, please contact the community liaison via phone or email anytime, day or night:


The 23rd Avenue Corridor Improvement project includes three phases:
Phase 1: S Jackson St to E John St: June 2015 – early 2017 (approximately 20 months)

  • Zone A - S Jackson St to E Cherry St: June 2015 – spring 2016; Zone A reopened to two-way traffic on March 14, however, construction activities are ongoing
  • Zone B - E Cherry St to E Union St: November 30, 2015 – summer 2016; current detour; early utility work completed
  • Zone C - E Union St to E John St: spring or summer 2016 – early 2017; early utility work completed

Phase 2: S Jackson St to Rainier Ave S- construction starts in 2017 (pending additional funding)

Phase 3: E Roanoke St to E John St – transit stop improvements only – construction starts in 2017 (pending additional funding)


For a good introduction to the project, be sure to check out our overview video.

The Corridor

23rd Ave is an essential arterial that connects a variety of users to businesses, educational institutions and residences in the Central District and beyond. Approximately 13,400-20,000 vehicles use 23rd Avenue each day. This area also serves high volumes of pedestrians, bike riders, and transit users (approximately 6,000 daily transit riders).

Why is the project needed?
The corridor is in poor condition. Currently on 23rd Avenue, there are:

  • Many collisions (more than 900 reported in five years)
  • Poor road conditions (e.g. potholes, cracked pavement)
  • Narrow lanes
  • Back-ups created by left-turning vehicles
  • Narrow and uneven sidewalks
  • Inadequate buffers between vehicles and pedestrians

Improving safety and mobility in your neighborhood

In June 2015, the Seattle Department of Transportation (SDOT) began construction on 23rd Avenue between S Jackson St and E John St. This is the first phase of a project to improve safety and mobility for people who drive, walk, bike and take transit in the area.

Project improvements vary by phase and include:

  • Modifying 23rd Ave from a four-lane street to a three-lane street - one lane in each direction with a center left-turn lane (key intersections will stay four lanes)
  • New pavement
  • Widening sidewalks to at least five feet and repairing broken and buckling sidewalks
  • Installing new streetlights
  • Upgrading traffic signals to give transit priority at key locations
  • Consolidating bus stops to improve transit speed
  • Replacing a 100-year-old water main that runs underneath 23rd Ave
  • Installing public art near 23rd Ave and E Union St
  • Implementing a greenway adjacent to 23rd Ave, to create a quieter, safer route for people to bike and walk

The new roadway –opportunity for a safer 23rd Ave

The new corridor will have wider lanes – one in each direction – plus a 10-foot-wide center turn lane. The turn lane will allow left-turning vehicles to make a safe left turn, while still allowing thru-traffic to continue through an intersection and down the street.

On streets with 25,000 vehicles per day or fewer, such as 23rd Ave, changing the street design from four lanes to three can increase safety by reducing collisions, reducing speeding, allowing vehicles to turn without blocking traffic, managing drivers cutting in and out of lanes, creating space for wider sidewalks, making streets easier to cross and making it easier for freight and transit to travel. At most bus stops, the road will flare to approximately 18 feet, where buses can pull to the side and vehicles can pass the stopped bus in the travel lane. The City is also working with King County Metro to determine the benefits of electrifying the Route 48 line. The results from the study can be found in the Project Materials section below.

cross section

Public Outreach

SDOT is committed to engaging with the community and understanding the needs in the project area. To get ready for construction,we are conducting door-to-door outreach, briefing community groups and businesses, sending email and online notifications, and hosting a pre-construction open house. Please contact us if you would like to request a community briefing.

To receive project email updates, sign up below!

Email address:

Project Materials

Current materials

Translated materials

  • Phase 1 Construction Handout


Previous materials

Project Cost

SDOT has a total of $43 million in funding through a combination of local, state and federal sources. Phase 1 is estimated to cost approximately $31 million and is fully funded. SDOT has sufficient funding for Phase 2 and 3 design; however, additional funding is needed for Phase 2 and 3 construction.

Questions or Comments?


Call the 24-hour project construction hotline: 206-727-8857

Maribel Cruz
Project Communications Lead

Therese Casper
Project Manager

To request information in another format:

If you need this information translated, please call (206) 727-8857.

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