Interstate 405

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Interstate 405

Interstate 405 is an urban loop encircling Seattle along a 30.32 mile long route from Tukwila in King County to Lynwood to Snohomish County. The commuter freeway heads east from I-5 and the freeway along SR 518 into Renton, where it turns north around Lake Washington to Newcastle and Bellevue.

I-405 meets I-90 in Bellevue by Mercer Slough Nature Park. North from there, I-405 passes east of Downtown en route to the freeway along SR 520 to Seattle and Redmond. Continuing north, the loop passes through the city of Kirkland before turning northwest through Bothell to I-5 at SR 525.

Interstate 405 Washington Guides

North - Tukwila to Bellevue - 58 photos

North - Bellevue to Lynnwood - 30 photos

Interstate 405 south at Washington State Route 520 in Bellevue

South - Lynnwood to Bellevue - 57 photos

Interstate 405 south at Coal Creek Parkway in Bellevue, Washington

South - Bellevue - 57 photos

Seven miles of I-405 were completed by 1966 from Tukwila to May Creek at a cost of $12.623 million.1 Interstate 405 opened entirely with at least two lanes north to Lynwood by the end of 1969.2

I-405 south at the former Wilburton Tunnel in Bellevue, Washington

A historical look at the Wilburton Tunnel on I-405 south formerly located west of Woodbridge in Bellevue. The tunnel was demolished on August 16th, 2008 as part of a WSDOT freeway widening project ("Wilburton Trestle", 2010). An abandoned BNSF Railroad line traveled above the tunnel. Expansion south to I-90 widened I-405 to ten overall lanes and included a new southbound roadway through the multi level interchange at Exit 11. - 08/31/2006

Interstate 405 scenes
SE 8th Street at the diamond interchange (Exit 12) with I-405 in the city of Bellevue. Pictured here was an HOV-dedicated turn lane onto I-405 south. Construction associated with the I-405 expansion between Exits 12 and 10 (I-90) added an HOV-lane to the ramp from SE 8th Street east at 118th Avenue SE.

SE 8th Street at the diamond interchange (Exit 12) with I-405 in the city of Bellevue. Pictured here was an HOV-dedicated turn lane onto I-405 south. Construction associated with the I-405 expansion between Exits 12 and 10 (I-90) added an HOV-lane to the ramp from SE 8th Street east at 118th Avenue SE.

08/31/06

A two lane ramp (one general purpose, one HOV) joins Interstate 405 north from SE 8th Street from under the flyover to 116th Avenue SE north and the Lake Hills Connector east.
3 photos

A two lane ramp (one general purpose, one HOV) joins Interstate 405 north from SE 8th Street from under the flyover to 116th Avenue SE north and the Lake Hills Connector east.

08/31/06

Beyond the SE 8th Street ramp to Interstate 405 north is the historic Wilburton Trestle, a railroad bridge dating back to 1904 along a defunct BNSF Railroad line ("Wilburton Trestle", 2010).

Beyond the SE 8th Street ramp to Interstate 405 north is the historic Wilburton Trestle, a railroad bridge dating back to 1904 along a defunct BNSF Railroad line ("Wilburton Trestle", 2010).

08/31/06

All traffic bound for Interstate 405 south departs SE 8th Street via a single turn lane. The entrance ramp expands to three lanes (two general purpose and one HOV).
2 photos

All traffic bound for Interstate 405 south departs SE 8th Street via a single turn lane. The entrance ramp expands to three lanes (two general purpose and one HOV).

08/31/06

Interstate 405 signage posted along 114th Avenue SE between the park and ride lot and SE 8th Street at Exit 12.
2 photos

Interstate 405 signage posted along 114th Avenue SE between the park and ride lot and SE 8th Street at Exit 12.

08/31/06

Button copy overhead at the former cloverleaf joining NE 85th Street with Interstate 405 at Exit 18. Road work from 2022 to 2027 rebuilds this exchange into a three-level dogbone interchange.
4 photos

Button copy overhead at the former cloverleaf joining NE 85th Street with Interstate 405 at Exit 18. Road work from 2022 to 2027 rebuilds this exchange into a three-level dogbone interchange.

07/20/23

References:

  1. "Highway Improvements Tallied." The Daily Chronicle (Centralia, WA), September 14, 1966.
  2. "Modern Road Travel is Faster and Safer." The Daily Chronicle (Centralia, WA), May 24, 1969.

Wilburton Trestle. (2010, November 9) In Wikipedia. https://en.wikipedia.org/w/index.php?title=Wilburton_Trestle&oldid=395683611

Photo Credits:

Connect with:

Interstate 5Interstate 5
Interstate 90Interstate 90
Washington State Route 520State Route 520
Washington State Route 525State Route 525

Page Updated Thursday September 18, 2025.