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I-5 Study

Planning study news

The I-5 Master Plan is now coordinating with the Cascadia High-Speed Rail study to address the future transportation needs of Western Washington communities. The integrated Cascadia High-Speed Rail and I-5 Program allows us to look holistically at highway, rail, and other travel options.

Initial phase complete, next phase begins in early 2024
In progress


In Spring 2022 the Legislature initiated the Move Ahead Washington funding package to create planning and environmental linkages studies for Interstate 5. This work will ultimately create a master plan for the critical I-5 corridor that meets current and future transportation needs, and reflects WSDOT’s strategic plan, which includes resiliency, equity and workforce development goals.

As part of the comprehensive I-5 Master Planning effort, WSDOT has completed the following areas of work as of July 2023:

  • Developed an initial assessment of seismic risk and recommendations for future analysis for I-5 from Boeing Field to Lake City Way.
  • Developed near-term recommendations for improving the HOV system and evaluated other techniques for making the HOV system more efficient.
  • Conducted 91 listening sessions with key jurisdictions and other stakeholders statewide and developed an interim report on Master Plan recommendations for I-5 that will identify future decision-making and engagement opportunities. Work on the next phase of the I-5 planning work, including the Master Plan will continue in early 2024.
The I-5 Study area; the study will assess the corridor and provide PEL and HOV system recommendations and conduct an initial seismic risk assessment and recommend future analysis.