I-405 South Bellevue Widening

I just wanted to extend my congratulations for a job well done over the past two weekends ... a well coordinated and communicated job gives the best results. Your messages were clear and understandable and we consider this joint effort one of our best examples of the business model the Washington State Department of Transportation (WSDOT) aspires to.
Paula Hammond, Secretary of Transportation, Washington State Department of Transportation
Bellevue, Washington
Washington State Department of Transportation
Year Completed: 

Atkinson added new lanes to Interstate 405 between 112th Avenue SE and SE 8th Street as part of the I-405 South Bellevue Widening project. The project relieves congestion at one of I-405's worst bottlenecks, the drive in and out of downtown Bellevue. The Atkinson project team was recognized for developing and implementing a comprehensive safety training program and a community outreach campaign.

A design-build project, the I-405 South Bellevue Widening expanded four miles of roadway between 112th Avenue SE and SE 8th Street. Crews built a new northbound lane from 112th Avenue SE to SE 8th Street and a new southbound lane from SE 8th Street to I-90. As part of the project, crews also demolished the old 300-foot Wilburton tunnel, a cast-in-place concrete tunnel supporting an abandoned railway line. Removal of the tunnel allowed for the expansion of the freeway to six lanes where the tunnel once restricted traffic flow to four lanes. Additionally, Atkinson widened several bridges, built a new southbound bridge over I-90, repaired pavement in both directions, and restored an area wetland.

The Wilburton Tunnel's successful demolition and removal required closing southbound I-405 for three weekends. Community outreach and communication were critical: if a significant amount of traffic was not diverted from the road during the closures, traffic engineers estimated backups could extend 13 miles, potentially causing a domino effect of gridlock on Seattle-area highways. The project team, in conjunction with Washington State Department of Transportation (WSDOT) officials and the city of Bellevue, developed a comprehensive communication strategy to prepare for Wilburton Tunnel's removal. The plan identified key messages, audiences, and tactics for building awareness of the closures. The team held several media events at the jobsite and reached out to local businesses, community groups, and social services. A road closure fact sheet was printed, translated into five languages, and distributed to local organizations. 


The Atkinson I-405 South Bellevue Widening project team developed and implemented a program that addressed the safety of project workers, subcontractors, WSDOT employees, and the surrounding community. The safety training program integrated safety into the jobsite culture, which led to a reduction in recordable incidents. The project team earned two Roadway Work Zone Safety Awareness Awards from the American Road & Transportation Builders Association's Transportation Development Foundation (ARTBA-TDF) for their jobsite and community outreach efforts. 

American Road & Transportation Builders Association - Roadway Work Zone Safety Award