Innovation loops drivers around I-405 construction zone

By guest blogger Anne Broache

If you’ve ever struggled to navigate the congested area where northbound Interstate 405 meets State Route 522 in the Bothell area, rest assured that improvements are on the way. As part of the I-405 NE 6th Street to I-5 Widening and Express Toll Lanes Project, our project crew will add a new set of ramps—called “braided ramps”—that separate traffic going from Northeast 160th Street to northbound I-405 from I-405 traffic heading to SR 522.

But before we can make this upgrade, we had to innovate to keep ramp traffic—some 13,000 vehicles daily—moving through the braided ramp construction area. To avoid repeated shutdowns of this critical on-ramp, our contractor worked this summer to build a temporary loop ramp to northbound I-405 at NE 160th Street. We’ll be able to route traffic around the construction rather than through it.

We’ll soon be ready to open that new ramp and shut down the current one.

New I-405 on-ramp at NE 160th Street opens September 8
Starting as soon as Sunday, September 8, drivers will access the on-ramp to northbound I-405 from the south side of NE 160th Street, just east of I-405 and adjacent to the northbound off-ramp from I-405.

The new entrance will be located directly across NE 160th Street from the existing on-ramp entrance, as shown in the map below.

New temporary on-ramp to I-405
The on-ramp you’re accustomed to using will remain closed until the new braided ramps open in 2015.

This temporary on-ramp has clear advantages:
  • It creates a dedicated work zone for our crews. By shifting traffic off the existing on-ramp, we can give crews full access to work on the new ramps in a space without public access.
  • It prevents major traffic interruptions. The temporary on-ramp will allow us to provide consistent northbound I-405 access instead of making multiple changes to the existing on-ramp as construction reaches different phases.
  • It’s the neighborly thing to do. Maintaining access to I-405 around the work zone allows more construction activities to happen during daytime hours, reducing nighttime noise for neighbors.
Allow extra travel time when the new ramp opens
As with any new roadway configuration, drivers should allow extra time to navigate and approach the new on-ramp—especially in the first few weeks while drivers get used to the new arrangement. Opening the new temporary ramp depends on good weather, and we’ll be sure to update drivers if the schedule changes.  

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