SR 520 - 148th Ave NE Interchange - Overlake Access Ramp

Project news

  • This Connecting Washington project will replace the existing eastbound SR 520 ramp at 148th Avenue Northeast to improve traffic movement through the area.
  • Design work is scheduled 2019-21; construction is scheduled 2021-25.
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Why is WSDOT replacing the interchange of eastbound SR 520 and southbound 148th Avenue Northeast?

The current eastbound SR 520 ramp to southbound 148th Avenue Northeast creates heavy congestion in the Overlake area of Redmond, particularly at the 148th and Northeast 24th intersection. In addition, the city of Redmond is planning for residential and retail business development east of 148th in part because Sound Transit is building a light rail station along SR 520 in that area.

To improve traffic movement in this area, WSDOT will build:

  • A new SR 520 off-ramp just north of the existing one for drivers who want to go south on 148th Avenue Northeast.
  • A tunnel under 148th Avenue and extend the current SR 520 off-ramp to go underneath 148th.

The new SR 520 off-ramp underpass will take people into the area between 148th and 152nd avenues, where they can get to the light rail station, businesses and residences. They can also use this route to take either 151st or 152nd Avenue to reach 24th Street.


The End Result
A new ramp will take people driving from eastbound SR 520 to southbound 148th Avenue Northeast, while the rebuilt ramp that goes under 148th Avenue will take people who drive into Redmond’s redeveloped neighborhood and light rail station south of SR 520.

Project Benefits
Rebuilding the existing ramp will make it easier for drivers to continue east of 148th Avenue Northeast, reducing the backup on the eastbound SR 520 off-ramp and reducing the opportunity for collisions on the off-ramp. It will also reduce the need for drivers who want to go east on Northeast 24th Street to weave through traffic. This also limits the chance for a collision.

Congestion relief
Allowing drivers to continue east of 148th Avenue Northeast without stopping at the current intersection will reduce backups on the existing ramp. These backups can reach onto the HOV lane on SR 520. The reconfigured ramp also will improve access to a Sound Transit light rail station that will be built east of 148th Avenue Northeast.

What is the project timeline?
2019-2021: Design, engineering and right-of-way acquisition
2021-2025: Construction

Financial Information
This project is funded as part of the $16 billion Connecting Washington transportation package approved by the state Legislature in 2015. Connecting Washington projects will enhance the statewide transportation system and maintain critical infrastructure.


Financial Data for PIN 152032G, 152032K
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $1,100
CWA $68,000
Total $69,100


How can I get more information?

Tom Pearce
WSDOT Communications