Project Refinement Process


Voters approved funding for I-405 BRT in Fall 2016 as part of the Sound Transit 3 (ST3) Plan, which established the representative project. ST3 identified the high-capacity transit mode (BRT), the 11 BRT station locations and the parking facilities that would be developed as part of the project. 


In 2018, Sound Transit developed refinements to the representative project based on technical analysis and stakeholder input. The project objectives and evaluation criteria guided the process. Technical analysis included collecting information on existing conditions along the I-405 corridor through coordination with WSDOT, cities, transit agencies, and other local and regional partners. Sound Transit will continue to refine the project before requesting Board approval to advance the project into Conceptual Engineering and more detailed evaluation (including environmental review) in 2019.

Project Objectives and Evaluation Criteria


  • Improve speed, frequency and reliability in the corridor
  • Increase regional mobility
  • Deliver the project on-time and within budget
  • Develop stations to support safe and convenient access for multiple modes
  • Encourage equitable transit-oriented development
  • Promote a healthy and sustainable environment

Evaluation Criteria

  • BRT Travel Time
  • Service Reliability
  • Non-motorized Access
  • Transit Access
  • Vehicular Access