I-5 Near JBLM: A Decade of Collaboration, Innovation, and Progress
For more than a decade, the I-5 corridor near Joint Base Lewis-McChord (JBLM) has been known as one of the most congested and challenging stretches of highway in Washington State. High volumes of freight traffic, military access requirements, regional commuter demands, and environmental considerations all converge within a tight eight-mile segment.
Solving a problem of this scale doesn’t happen with a single idea or a single project. It takes patience, creativity, collaboration — and a willingness to find a way forward, even when the path isn’t obvious.
That mindset has guided SCJ Alliance’s work on multiple projects in the JBLM vicinity, including the I-5 JBLM Vicinity Congestion Relief Project and the Berkeley Street/Jackson Avenue Interchange, both critical pieces of WSDOT’s broader I-5 Mounts Road to Thorne Lane Corridor Improvements program.
Planning for Progress in a Constrained Environment
SCJ led planning, engineering, and NEPA Environmental Assessment (EA) efforts for a comprehensive multimodal alternatives analysis along I-5 near JBLM. The goal was clear but complex: reduce congestion, improve freight and passenger movement, and enhance community connectivity — all while balancing environmental, military, and regional needs.
The aggressive project schedule required a creative approach to stakeholder engagement and coordination. Over the course of the effort, SCJ worked closely with 14 agency partners and engaged more than 60 stakeholders, including WSDOT, JBLM, local jurisdictions, and the public. Continuous communication and transparency were essential to keeping the process moving and building trust across diverse interests.
As a key priority project for the state, the work emphasized least-cost planning and practical design, integrating transportation and environmental considerations from the outset. That approach paid off. Approval of the NEPA EA advanced the project toward design-build delivery and, through a collaborative process, resulted in more than 40% cost savings compared to the original planning estimate — without compromising performance or outcomes.
Designing for Mobility, Security, and Community
SCJ’s role on the Berkeley Street/Jackson Avenue Interchange (Exit 122) further demonstrates the importance of adaptable thinking in constrained environments.
As part of the I-5 corridor widening through JBLM, SCJ helped design and deliver a reconfigured interchange featuring a dogbone roundabout, providing grade separation over the railroad right-of-way west of I-5. The location of the new bridge was carefully selected south of the existing crossing to minimize construction impacts to both the City of Lakewood and JBLM.
SCJ prepared 30% concept plans used in the design-build RFP and coordinated extensively with WSDOT, JBLM, the Army Corps Center of Standardization in Omaha, the City of Lakewood, and the Washington National Guard. Meeting current military security requirements added another layer of complexity, particularly with the reconstruction of the Madigan Access Control Point (ACP) approach zone.
Right-of-way constraints required an unconventional solution: an asymmetrical, egg-shaped roundabout designed to accommodate Camp Murray’s design vehicles and security needs — a practical example of how creative design can solve very real operational challenges.
From Planning to Reality: Seeing the Results
That long-term planning and coordination is now becoming tangible. In January 2026, WSDOT opened the first phase of the new diverging diamond interchange at Steilacoom-DuPont Road, allowing southbound traffic to begin using the new overpass and roundabout. The full interchange is expected to open this spring, bringing major changes to traffic flow and safety along I-5 near JBLM.
The new overpass increases vertical clearance, eliminates an at-grade railroad crossing, improves pedestrian access, and supports the extension of HOV lanes further south into DuPont. It’s a visible reminder that complex, multi-agency projects — when approached thoughtfully — can deliver meaningful improvements for communities, commuters, freight, and military operations alike.
Finding a Way Forward
Projects like these don’t succeed by chance. They succeed because teams are willing to ask better questions, rethink assumptions, and collaborate across agencies and disciplines.
At SCJ, “Find a Way” isn’t about ignoring constraints — it’s about working within them creatively and responsibly. Whether it’s navigating NEPA processes, coordinating with military partners, or designing within tight right-of-way limits, the ability to adapt and problem-solve is what moves projects forward.
As improvements along I-5 near JBLM continue to take shape, we’re proud to have played a role in helping WSDOT and its partners transform one of Washington’s most challenging corridors — and to continue finding ways to deliver smart, practical, and lasting transportation solutions.
Jan 27, 2026 | Cathy McKay | Projects in Action