Tunnels and Skyways: High-Stakes Decisions in Urban Hospital Infrastructure
What hospital leaders need to consider when planning campus connectors
Read time: 7 mins
Hospital campuses are under constant pressure to grow, modernize, and optimize—often while remaining fully operational and financially disciplined. Across both dense urban campuses and large regional hospital campuses, hospital tunnels and skybridges frequently become high-stakes infrastructure decisions, shaping staff efficiency, logistics flow, patient movement, safety, and long-term campus flexibility. Yet despite their outsized influence on daily operations and patient experience, these connectors are often treated as supporting infrastructure rather than strategic assets in long-range planning.
For health system leaders, the question isn’t whether connective infrastructure adds value—it’s how and when to invest in solutions that protect clinical operations while supporting both short- and long-term campus growth. These decisions require careful planning, sequencing, and execution, particularly when construction occurs alongside active care environments with little tolerance for disruption.
The case studies that follow illustrate how three health systems evaluated tunnel and skybridge investments, navigated planning and execution challenges, and achieved measurable operational outcomes. While each campus faced different constraints, they share a common lesson: early, intentional decision-making around connectivity leads to better results during construction and long after.
CASE STUDY 1
Building an “Impossible” Tunnel Under an Active Hospital Campus
Allina Health | Abbott Northwestern Hospital
Challenge:
What once required more than 30 cart trips across an eight-hour shift each night had become a persistent operational challenge at Abbott Northwestern Hospital. Supplies were moved across a public skyway—highly visible, inefficient, and misaligned with the care environment Allina Health was working to create. Rather than managing around the problem, Allina Health made a deliberate decision to rethink logistics at the campus level.
Early planning explored surface‑level fixes and operational workarounds, but none addressed the root issue. The most effective solution—a dedicated underground tunnel—was also the most complex. It required construction beneath a massive, concrete‑encased electrical high voltage duct bank and other city utilities, ultimately connecting to a new elevator that extended beneath an existing building on campus. This complexity introduced significant structural and operational risk. Rather than asking whether the tunnel could be built, Allina Health and Mortenson reframed the challenge around a more critical question: how could it be delivered safely beneath a fully active hospital campus?
Solution:
That decision shifted the project into a problem-solving phase. Through close collaboration among Allina Health's facilities leaders, designers, engineers, and Mortenson, the team developed a path to protect critical utilities, manage complex excavation, and construct new infrastructure without disrupting patient care or city services. The result is a 480‑foot underground tunnel that fundamentally changes how materials move across the Abbott Northwestern Hospital campus.
Outcome:
What was once a nightly, labor‑intensive process is now handled through a dedicated, out‑of‑sight logistics pathway—reducing staff burden, improving the patient and visitor experience, and saving significant operational costs each year. Delivered without interrupting hospital operations or city infrastructure, the tunnel strengthens Allina Health's long-term logistics strategy and demonstrates the power of decision-driven, contraint-aware planning.
A 480-foot underground tunnel designed to streamline material movement across the Abbott Northwestern Hospital campus.
CASE STUDY 2
Designing Campus Connectivity Around Clinical Reality
Providence Swedish | First Hill Campus
Challenge:
To promote an integrated healing environment across its First Hill campus in downtown Seattle, Providence Swedish expanded its skyway network by adding a new 20-foot skybridge linking legacy buildings to the new Hughes Tower—a more than 700,000-square-foot expansion anchoring the campus transformation.
Early planning focused on how clinicians and patients move through the campus each day, while accounting for a vertically complex hospital landscape and the realities of adding a new skybridge to an active, coordinated network.
As planning advanced, floor alignment quickly emerged as a defining constraint. While the lower podium floors naturally connect with the Southwest Tower across key levels, the buildings fall out of alignment above the podium as floor-to-floor heights diverge—driven in part by higher ceiling requirements on surgical floors. This made Floor 8 the only viable alignment point, enabling an efficient connection without unnecessary vertical shifts or elevating the bridge beyond what was operationally needed.
Solution:
Floor 8 emerged as the only viable alignment point, allowing a direct and efficient connection without unnecessary vertical transitions or raising the bridge beyond operational needs.
Equally important, Providence Swedish consciously avoided locating the skybridge on operating room floors. Surgical environments are designed to remain secluded from general hospital circulation to support infection control, privacy, and operational integrity. Placing the connection on Floor 8 allowed Providence Swedish to maintain that separation while still enabling a direct, intuitive link between adjacent inpatient and support environments.
Outcome:
The resulting skybridge placement balances structural feasibility with clinical priorities—minimizing unnecessary staff travel, preserving surgical zone integrity, and improving continuity for patients navigating the campus.
In parallel, the project team is also preserving and re-integrating a second skybridge over Marion Street, connecting directly into Hughes Tower and transforming a former link between two demolished buildings into an active connection serving the expanded campus, including the Swedish Cancer Institute.
Together, these decisions reinforced a campus circulation strategy that prioritizes staff experience, patient safety, and long-term operational resilience.
Rising in the heart of downtown Seattle, Providence Swedish’s Hughes Tower opens in 2027.
CASE STUDY 3
Early Skybridge Delivery to Improve Access and Patient Experience
Froedtert ThedaCare Health | Milwaukee Regional Medical Center
Challenge:
As part of the West Tower expansion, Froedtert ThedaCare Health set out to redefine the front door to Froedtert Hospital—one of Wisconsin's largest academic medical centers—ensuring arrival infrastructure could support a 781-bed, Level I Trauma Center with significant daily patient and visitor volume.
While the campus expansion will continue across multiple years, the skybridge needed to be delivered early to support day-to-day access and mobility—coming online alongside a 230,000-square-foot tower under construction and spanning the campus's busiest internal thoroughfare without ever fully closing it.
Solution:
Early alignment between Froedtert ThedaCare Health and Mortenson advanced the skybridge completion more than a year ahead of the broader West Tower construction, supporting immediate access between active parking structures and clinical services.
Patient experience guided the final configuration. Instead of routing patients through active construction, the skybridge includes a direct garage connection alongside a future Tower lobby tie-in—shortening travel distances and creating a clear, intuitive arrival from day one. This approach also reduced the need for temporary safety measures, delivering significant cost savings and simplifying site operations.
To maintain campus mobility during installation, the internal roadway closure was limited to just three carefully coordinated weekend windows—avoiding the two months of phased shutdowns typically required under a traditional construction approach. Outside those weekends, normal traffic patterns were maintained. This was enabled by assembling large steel sections on-site and utilizing prefabricated concrete floor and ceiling planks, allowing crews to set major components efficiently and safely within tight windows.
Outcome:
Now complete, the skybridge provides a high-capacity, protected connection that supports daily hospital operations. Delivered early, the result is a calm, intuitive arrival experience that reinforces Froedtert ThedaCare Health’s commitment to safety, accessibility, and continuity of care—while supporting campus growth.
We viewed the skybridge as essential campus infrastructure, not a later add-on. Delivering it early supported patient access, simplified campus operations, and positioned the hospital for future growth.
The Long-Term Value of Connectivity
The common thread and consistent truth: long-term value of hospital tunnels and skyways is shaped less by the structure itself and more by when and how the decision is made.
Opportunity: When planned early and aligned with a broader campus strategy, connective infrastructure can support operational continuity, improve logistics efficiency, reduce staff friction, and preserve flexibility as care models evolve.
Risk: When deferred or treated as an afterthought, it can introduce avoidable risk, inefficiency, and long-term limitations.
Key Takeaways for Resilient Hospitals
- Long‑term value is shaped by how connective infrastructure decisions are made and integrated into campus strategy, not by the structure alone
- Early integration supports operational continuity, logistics efficiency, care delivery workflows, workforce experience, patient satisfaction, and campus‑wide flexibility
- Reactive or deferred decisions introduce avoidable operational risk, inefficiency, and long‑term constraints
- The most resilient hospital campuses treat tunnels and skyways as strategic infrastructure investments, not conveniences