Harrison and Mercer Transit Access Project

Transit priority, pedestrian amenities, pavement upgrades, traffic signal adjustments and road layout/curb space modifications, landscaping

Updated: May 2025

About the Project

The Seattle Department of Transportation is designing a new east-west transit corridor in South Lake Union, to support faster, more reliable connections to future nearby transit options, like Sound Transit Link Light Rail station and Metro bus routes.

The Harrison and Mercer Transit Access Project will improve connections between South Lake Union and the Uptown/Lower Queen Anne neighborhoods. 

This project aligns with King County Metro’s long term transportation plan, called Metro Connects. The goal of this plan is to make transportation more frequent, reliable, and fast in King County by the year 2050.

Why is this Project Important?

The Harrison and Mercer Transit Access Project will improve east-west transit connections to make travel easier and more reliable. As South Lake Union and Uptown continue to grow, the need for dependable public transportation increases. This project supports that growth by making it more convenient and efficient to get around.

This project may include:

Maintenance and Modernization

• Rebuilding roadway areas, including paving and structural foundations when necessary.
• Upgrading drainage system by adding new catch basins and inlets to manage water effectively.

Transit Upgrades

• Adding new transit amenities along 5th Ave N, between Harrison and Mercer streets; and along Mercer St between Queen Anne Ave N and 5th Ave N.
• Transit amenities may include bus lanes, new and upgraded bus stops, and transit signal optimization for buses.  

Safety Upgrades

• Installing bus bulbs to provide a designated area for passengers to wait safely for their bus.
• Repairing and widening sidewalks to create more space and improve walkability.
• Enhancing crossings at:
  • 8th Ave & Harrison St
  • Terry Ave & Harrison St
• Adding Accessible Pedestrian Signals (APS) that use sounds and tactile signals to help individuals with blindness or low vision cross streets safely.
• Installing curb ramps to meet ADA (Americans with Disabilities Act) standards, making street crossings easier and safer for people using wheelchairs, strollers, or other mobility aids.

Map of Project Area

Map of Transit Options Connecting to Project Area

Timeline

1. Planning (2022-2023): We collected traffic data, developed concepts and gathered community experiences to develop initial 10% plans.  
2. Design (2023-2025): We’ll collaborate with stakeholders and community members to develop a more detailed final design.   
3. Construction (as soon as 2026): We will construct the project and keep the community informed on the latest construction updates, schedule, and expected impacts.    

Project Materials

• Fact sheet (2025)

Additional projects adjacent that this project is coordinating with: 

• Sound Transit South Lake Union Link Station
• Metro Eastlake Layover Facility
• RapidRide J Line
• WSDOT 520-to-Mercer Reversible Transit Ramp
• Thomas St (5th Ave N to Dexter Ave N)
• Denny Way Paving Project
• North Downtown Mobility Action Program 

Need a translation?

• For information about our study of future transit improvements on Mercer and Harrison Streets in your language, please call (206) 900-8717.
• 欲透過您的首選語言來了解我們對 Mercer 街和 Harrison 街未來公共交通改善的研究的資訊，請向我們發送電子郵件： HarrisonMercer@Seattle.gov，或撥打，或撥打206 – 900 – 8717 以您的首選語言留下語音訊息。
• Mercer 및 Harrison Street의 향후 대중교통 개선 연구에 대한 정보를 선호하시는 언어로 원하시는 경우, HarrisonMercer@Seattle.gov로 로이메일을 보내거나 206 – 900 – 8717로 전화하여 선호하는 언어로 음성 메일을 남겨주세요.
• Para obtener información en su idioma sobre nuestro estudio de las futuras mejoras del transporte público en las calles Mercer y Harrison, envíenos un correo electrónico a HarrisonMercer@Seattle.gov, o deje un mensaje de voz en su idioma preferido llamando al (206) 900-8717.