I-405 Northeast 85th Street Interchange and Inline BRT Station, WA
Image credit: © WSDOT
AAR Testing and Inspection, a SOCOTEC Company, provided materials testing, special inspections, and QA/QC oversight for the I-405 / Northeast 85th Street Interchange and Inline BRT Station Project, a new three-level multimodal interchange and transit hub in Kirkland, Washington.
Key Information
Project Name: I-405 / Northeast 85th Street Interchange and Inline BRT Station
Client: Graham Contracting LTD
Owner: Washington State Department of Transportation (WSDOT) & Sound Transit
Location: Kirkland, Washington
Funding: $210 Million
Services Provided: Construction Materials Testing, Special Inspection, QA/QC Oversight
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The Challenge
Modernizing a Key Multimodal Interchange
The I-405 / Northeast 85th Street Interchange and Inline BRT Station Project is a key component of the I-405/SR 167 Corridor Program, replacing an aging two-level cloverleaf interchange with a modern, three-level multimodal interchange designed to improve mobility throughout the region.
The project supports the future Sound Transit Stride Bus Rapid Transit (BRT) system while enhancing highway operations, strengthening local access, and improving connections between I-405, Northeast 85th Street, and surrounding communities.
Constructing this major transportation infrastructure project presented several challenges. Work had to be completed adjacent to active traffic, including the I-405 Express Toll Lanes, while maintaining safe travel and supporting phased construction activities. The project also required careful coordination between roadway, bridge, and transit infrastructure within a constrained urban corridor. Urban constraints further shaped traffic shifts and detour planning throughout construction. Complex geometry also had to tie together the express toll lanes, Northeast 85th Street, and future transit pathways.
Additional complexity came from integrating stormwater systems, utilities, grading activities, and temporary traffic alignments while meeting the quality requirements established by WSDOT and Sound Transit.
The SOLUTION
Supporting Construction Through Quality Assurance
AAR Testing and Inspection, a SOCOTEC Company, provided comprehensive materials testing, special inspections, and quality assurance/quality control (QA/QC) oversight throughout the early and active phases of construction.
Working alongside the project team, our professionals maintained a consistent field presence to verify construction quality, support phased sequencing, and help ensure roadway, bridge, and transit infrastructure met project specifications and owner requirements.
Through responsive inspection services, coordinated documentation, and technical expertise, our team supported efficient project execution across multiple work zones in this complex design-build environment.
Services Provided
The Results
Improving Mobility and Regional Connectivity
By providing comprehensive testing, inspection, and QA/QC services, AAR Testing and Inspection, a SOCOTEC Company, supported the delivery of a transformative transportation infrastructure project for the Kirkland community and the greater Puget Sound region.
The completed project improves mobility by replacing the outdated cloverleaf interchange with a modern three-level interchange that better integrates highway traffic, local roadways, and regional transit. It also prepares the corridor for the future Sound Transit Stride BRT system while improving access for motorists, pedestrians, cyclists, and transit users.
Project Highlights
- Modern three-level multimodal interchange
- Inline Sound Transit Stride BRT station supporting regional transit connectivity
- Improved connections between I-405, Northeast 85th Street, and surrounding neighborhoods
- Enhanced access for pedestrians, cyclists, transit riders, and motorists
