Project news

• This project is scheduled to advertise for competitive bid in fall 2020.
• Work is scheduled to begin in 2021.
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Overview 

Contractor crews will improve the mobility along a 2.51-mile stretch of northbound Interstate 5 from Yesler Way to Lakeview Boulevard through Seattle. Crews will:

• Add an additional lane between the Seneca Street off-ramp and the Olive Way off-ramp by replacing existing barriers, rails and curbs with a thinner barrier, reconstructing asphalt shoulders with concrete and restriping the roadway.
• Install ramp meters on the collector-distributor on-ramp and the Cherry Street on-ramp.
• Install nine new sign bridges, along with updated signing.
• Extend Active Traffic and Demand Management (ATDM) system north to State Route 520.

Needs and benefits

This section of northbound I-5 carries approximately 100,000 vehicles a day and includes a two-lane section that creates one of the worst traffic bottlenecks in the state. Traffic often backs up to Boeing Field and there are many congestion-related collisions throughout the day.

Crews will rebuild the existing Seneca Street exit-only lane to add a third lane through the current two-lane bottleneck after the Seneca Street off-ramp. This third lane will be open to all vehicles and for those exiting at Seneca Street.

To create a seamless transition to the existing four lanes of traffic after the Cherry Street on-ramp, crews will add an auxiliary lane from the Cherry Street on-ramp, which will end as an exit only lane at Olive Way.

What should drivers expect?

To avoid disruption of the high daytime traffic volume on I-5, there will be mainly nighttime lane closures and flagging in the work zone.

The End Result

This mobility improvement work is projected to improve traffic flow and reduce congestion delays. High-occupancy vehicles will benefit with an additional bypass lane on the mainline and collector-distributor on-ramp. The extended ATDM system is expected to reduce collisions by providing drivers with information about what to expect as far as congestion and/or incidents ahead.

Needs & benefits

• Improved safety: Extending the northbound I-5 ATDM system to SR 520 is expected to reduce collisions by adjusting speed limits based on conditions and providing drivers with information about what to expect as far as congestion and/or incidents ahead.
• Congestion relief: Traffic flow through the area should improve and reduce congestion delays.

Timeline

• Fall 2020: Advertise for competitive bids
• Spring 2021: Begin construction
• Fall 2022: Complete construction