Tunnel work begins for Overlake access ramp in Redmond

By Adrienne Hatmaker

I don’t think it’s a secret that Redmond and surrounding cities east of Lake Washington are among the fastest growing in this state. And if you frequent the Overlake area, you know how congested it gets heading to southbound 148th Avenue Northeast from the eastbound State Route 520 off-ramp. With new residential and retail development and the future Sound Transit Link light rail station, the area and traffic within Overlake will continue to grow.

Good news: The new Overlake ramp will help ease that congestion, and tunnel excavation for the new ramp begins in early May!

Crews have prepared the tunnel work zone on the east side of 148th adjacent to SR 520 ramps in Redmond. A temporary traffic signal and traffic shift will be used in early May and be in place for about four months.

As you might guess, building the tunnel and new ramp has a few stages involved and this is the first. Our contractor crews from Granite Construction will begin tunnel excavation on the east side of 148th so traffic flow will need to change.

The sidewalk on the east side of 148th, adjacent to the SR 520 ramps, has been removed for tunnel work. Pedestrians have access to the west side of 148th during this part of the project.

What you can expect

The speed limit in the work zone will be lowered to 30 miles per hour, lanes approaching the interchange will narrow and shift to the west side of 148th. We’ll add a temporary traffic signal system to guide travelers through the interchange and pedestrian access will be on the west side of 148th only. This phase of the project will take about four months to complete.

In this four-month phase of work, traffic lanes will narrow and shift west along 148th to give crews room for tunnel excavation on the east side of the road. Pedestrians can access the sidewalks on the west side.

The next phase of the project will have the Granite crews excavating the tunnel from the west side of 148th before building the new ramp. That will mean flipping traffic to the east side with a lower speed limit and more narrow lanes. When complete in summer 2023, drivers will have easier access from eastbound SR 520 to residences, businesses and the future light rail station.

Making it easier to get around

This project will bring many benefits to people who travel in the Overlake area, including:

• Improved mobility. The existing eastbound off-ramp to 148th Avenue Northeast will be realigned and a second off-ramp added that will cross under 148th Avenue Northeast. This will provide a new eastbound exit option from SR 520.
• Direct access. The new off-ramp will provide direct access to the Overlake Village retail area.
• Improved safety. The new routes from SR 520 will reduce off-ramp backups and weaving traffic on 148th Avenue Northeast, decreasing the potential for crashes.
• Improved street connections. We will coordinate with the city of Redmond on new city street connections, providing travelers timely access to the Overlake Village Link light rail station and 152nd Avenue Northeast.

This $68 million project is funded through the 2015 Connecting Washington transportation package, which provides a $16 billion investment in the statewide transportation system.

We understand that during the next year or so this work will create challenges for people traveling in the Overlake area. In the end though, this new ramp and tunnel will make it easier for you to get where you're going.