South Downtown I-405 Access Study

Header Image
I-405 corridor in Bellevue

Bellevue continues to grow, with the new East Main light rail station opening in 2023, plans to further develop south downtown Bellevue and expanded toll lanes on Interstate 405 opening in 2024. To minimize traffic congestion and help people get where they need to go, whether they are walking, biking, riding transit or driving, the city and the state Department of Transportation are partnering to study a new interchange to access I-405 in south downtown Bellevue.

Study Underway

Vicinity map of the South Downtown I-405 Access Study
Access Study Vicinity Map. Click image to enlarge

The I-405 Master Plan envisions a new interchange in Bellevue, south of Northeast Fourth Street. We are developing, evaluating and identifying options to complete as part of the I-405 Master Plan.

Proposed development along 114th Avenue Southeast, near the East Main light rail station and within the Wilburton area has created a pressing need to identify a preferred interchange option. Selecting a preferred option will enable the city to communicate to property owners and developers about right-of-way needs and site access options.

We need to develop a cost estimate to seek future funding opportunities.

This study builds upon WSDOT’s 2015 analysis where they evaluated eight potential access options at several locations between Northeast Second Street and Southeast Eighth Street.

City Council Consideration

The City Council, in collaboration with WSDOT, will select a preferred alternative informed by technical analysis and community input. The State Legislature has the ultimate decision-making authority to fund the project.

On Sept. 28, 2020, the City Council received an update on technical evaluation and community engagement. The council unanimously approved further study of the following five alternatives, suggested additional environmental considerations and encouraged prioritization of bicycle and pedestrian amenities. The staff memo and meeting video links can be found on the City Council agenda page

  • Lake Hills Connector southbound on-ramp;
  • Southeast Sixth Street extension with a southbound on-ramp;
  • Southeast Sixth Street extension with express toll lane access to and from the south;
  • Northeast Second Street extension to the Wilburton area; and
  • No new interchange.

The five alternatives will be further studied for factors such as travel time, access, safety, bike, transit and pedestrian integration, property and environmental impacts, consistency with city policies and cost. Staff will seek further community input.

For additional project history and background, read the overview


The study schedule for the I-405 access study

Community engagement

The city is engaging people who live, work or travel through the study area through interviews, forums and online open houses to gain perspective on options to improve access in south downtown Bellevue. We aim to share the purpose and need of the study, interchange options, the evaluation process and gather community input.

  • Online Open House, Aug. 3-21, 2020.: Over 200 surveys were received during the first open house. 
    • Summary of Aug. Online Open House (Sept. 2020)

Study materials

Outreach materials