In Midwestern cities, airports are car intensive. They are increasingly ringed by parking structures—and not attractive ones. Thankfully, this can change. The new Silver Ramp at the Minneapolis-St. Paul International Airport (MSP) showcases the possibilities for a more multi-modal future that is not yet here.
Designed by Miller Dunwiddie Architects (MDA) with Kimley-Horn as lead engineers, MSP’s Silver Ramp breaks the mold as an innovative work of architecture and engineering, a 21st-century echo of the optimism and innovation of airport architecture in the mid-century Golden Age of air travel. But this project also reflects the realities of our time—new technology, materials, and contemporary debates over American carbon output, car dependence, and the need for more transit options.
More than a Parking Ramp
When you enter MSP on the long entry drive, the Silver Ramp looms into foreground view. It’s an enormous, metallic, cube-like structure that glimmers with the changing daylight—a new kind of airport architecture that seems much lighter than it really is.
Despite its name, the Silver Ramp is more than a parking ramp. It serves as an intermodal hub and connection point for shuttle buses bringing passengers from the towns and small cities in MSP’s service area, passengers on the Blue Line light rail corridor connecting to the downtowns in Minneapolis and St. Paul, city buses, and even bicycles.
MDA’s lead design architect Phillip Koski has designed a broad spectrum of projects including office buildings for General Mills, the colorful 7th St. parking structure in downtown St. Paul and the light-filled expansion of Hennepin Methodist Church—a Minneapolis landmark designed by architects Hewitt & Brown with inspiration from the Abbey of Mont-St-Michel.
The Silver Ramp demonstrates Koski’s creative use of new materials and attention to detail, light, and color at a massive scale. Eleven stories high, the structure has 2.1 million square feet of structured parking for 5,000 vehicles, including levels 2–5 designated for car rental companies.
Koski’s architecture takes cues from Cerny Associates’ late-1950s design for MSP’s Lindbergh Terminal with its scalloped concrete roof, black- and color-glazed brick, and modern curtain walls. Thinking like a preservation architect, Koski documented Lindbergh’s “character-defining features”—one of which is that it is set atop a one-story plinth of black brick. This precedent continued though all of MSP’s subsequent expansions.
The Silver Ramp incorporates this tradition, as its dark pedestal contributes to its detachment from the ground. With a facade system that grows more reflective as it ascends, the structure appears to hover among neighboring concourses and parking ramps with an extraordinary sense of lightness.
The Structure is the Architecture
Kimley-Horn served as the project prime and lead for all civil, structural and traffic engineering disciplines. During the two-year predesign and design process, their collaboration with Miller Dunwiddie Architecture turned a major piece of parking infrastructure into a great work of public design. But this relationship didn’t happen overnight.
From schematic design through construction, each design team member was intently focused on solving any number of design challenges unique to their disciplines: Civil engineers designed the ramp over a continuously operating LRT station, structural engineers optimized bay spacing for the parking decks, mechanical engineers found pathways for all of their subterranean heating and cooling pipework. Because the decision had been made early to expose as many of the building systems as possible, every engineering decision became a de facto aesthetic choice as well. Koski began opening team meetings with the worthwhile reminder: “Now let’s remember, the structure is architecture, and the architecture is structure.”
Material and Color Mixing on the Exterior
Miller Dunwiddie’s abilities shine in the Silver Ramp’s five-acres of exterior cladding. The designers created a wall system with thousands of closely spaced of 2-inch by 5-1/2–feet tall terra-cotta fins (“baguettes”) glazed in four colors: black, gray, blue and white. Their placement, density, and tone miraculously seem to diffuse the bulk of the parking structure.
To create the aforementioned feeling of ascension, a perceptual trick used in numerous tall buildings, the mix of baguettes start dark at the ground and grow lighter toward the top. At the base of the Silver Ramp, the bottom row is a random mix of 95 percent black and 5 percent gray. The next row up is 87.5 percent black, 10 percent gray, and 2.5 percent blue. White is slowly added to the mix, while black is removed in subsequent higher levels and gray and blue are also diminished. The top course is 95 percent white and 5 percent blue.
The structural composition of the baguettes is another innovation. Airport communications are critical, so with FAA requirements of radar clarity and safety restrictions in mind, the design team worked with the local company M.G. McGrath to remove the baguettes’ standard aluminum structural core and replace it with a rigid fiberglass so that there would be no interference with MSP flight control. McGrath also suggested unitizing large groups of baguettes—40 to a panel—to speed up installation. The only metal included in the assembly are the structural aluminum shelf angles where the tops and bottoms of the panels are secured, in an effort to avoid radar deflection.
Constructability and Rule-Based Design
Given the enormous scale of the structure, the architecture team developed a system of design rules that could ensure consistency across the building’s 2.5-million square feet. “I knew this was going to be a very basic form,” Koski says. “But I also knew that we could give the interior and exterior some expressive discipline through revealing systems, highlighting patterns, creating repeating sequences and different scales.”
For color, size, and finishes in each area, the design, in order to remain coherent, adheres to a rule of four. For example: The exterior baguettes come in four colors, and the precast concrete panels have prescribed surface finishes that are limited to four textures, and terrazzo floors on the main level are composed of staggered panels of four shades of gray sizes. The surface becomes Mondrian-like composition recalling the loosely gridded farmland air passengers see when flying over the Midwest. (The formula also helped when finishing the lower level’s public spaces within the constraints of the project’s structural grid.) This discipline ensures that nothing draws undue attention to intersections, but also that each finish contributes to the space’s subliminal cohesion.
The voluminous ground-floor main lobby where the various transit modes converge is clad in white-oak paneling in two, three, four, and five foot modules, setting up a syncopation that enlivens the space without shouting. The color palette is restrained to the blond wood and mid-gray of the massive concrete columns that support the ten levels of parking above.
Rather than sheath the columns in sheetrock, Koski insisted that the material be left raw. In the elevator lobbies on all eleven levels the exposed concrete takes on a motley, rustic texture reminiscent of Italian travertine—budget chic. This sense of movement together with the changing light, polished concrete floors, and complementary concrete finishes (four in total, fittingly) recall the elegance of sophisticated Brutalist cultural and institutional spaces.
Even on the top level of the parking structure, open to the sky, the upper reaches of the stairwells and elevator penthouses are clad in thin precast concrete panels, again arranged in staggered bands in four shades of charcoal gray and four different sizes echoing the modular of the patterns in the building below.
A New Civic Space
The Silver Ramp’s soaring lobby is arguably one of the most beautiful public indoor spaces built in Minneapolis-St. Paul in the last thirty years—a remarkable achievement for a building that is essentially a massive parking structure. The coordination of colors, materials and patterns works to heighten the lobby’s spatial compression and release.
The main level is a point of contact and connection. Attendees at car rental counters greet customers while the adjacent transit lobby is the gateway to off-site parking shuttles along with city, regional, and charter buses. The central atrium connects visitors via escalator to the main terminal tram and regional light rail.
The four massive escalators to levels 2, 3, 4, and 5 really steal the show. Each of the four levels (and their associated car-rental companies) has its own escalator; as the levels rise, the escalators require increasingly longer runs, which creates a remarkable geometric ensemble when seen from the side and at their base.
The four escalators might be too alluring: They are such strong design and circulation elements that some travelers assume they lead to the main terminal—only to end abruptly at car rental pick up points. During a visit, we encountered a stream of people who had no idea how to reach the terminal. As we stood in the tall atrium space, we directed six people in just 20 minutes toward the discreet entry to the underground tram. (Ever ready, Miller Dunwiddie and the airport are already discussing possible solutions.) Wayfinding through both architecture and environment graphic design is a challenge for most large transportation projects.
Architecture for Public Services
What initially drove the creation of the Silver Ramp was the need for more public parking. Still, the airport also made the smart decision to invest in the Silver Ramp’s public spaces and areas for public transit. The current volume of shuttle and bus traffic is likely to grow, and the Silver Ramp will serve these needs well for decades.
MSP is ranked as roughly the 17th largest airport in the country in terms of passenger volume—with roughly 40 million annual arrivals and departures. There is no dense city next door; instead, a suburban mix of roads, airport support facilities, hotels, and more parking structures extends for miles. Inside the security checkpoints, the venue is advertised as the “Best Airport in North America,” (in terms of size) sporting niche shops, hair salons, top-notch dining, children’s play areas, and an indoor walking path. Yet, post 9-11, there are virtually no public services outside security. MSP’s Metropolitan Airport Commission has a long way to go in extending this vitality into places like the Silver Ramp.
MSP is adding public amenities in both the ticketing and baggage levels of the main terminal, but the work is not complete. Fortunately, the Silver Ramp’s public spaces are designed with the scale and space to accommodate more services in the future; this should be a top priority. This transit project is, in many ways, more beautiful and accommodating than many public buildings, but for now, with few reasons for its use, it is not a place to linger.
The million-dollar question is: Will the Silver Ramp become a true transit hub? Or will it remain just a parking garage with a nice screened facade? Is the vision of bringing multimodal transit to MSP possibly an act of greenwashing, which shallowly legitimates a structure that cost hundreds of millions of dollars, only to be occupied by gas-burning cars in a time of climate crisis?
Time will tell. There are improved waiting areas for shuttles and buses, ample bicycle parking (which goes largely unused today), and, most importantly, a direct connection to the LRT Blue Line, the most heavily used public transit corridor in the region. Improved wayfinding, increased ridership, and commercial activation could transform the Silver Ramp into a prime destination at the airport.
Design to Visualize New Options
We occupy a particular moment in which we both know the social and environmental tolls of car-based urbanism while, at the same time, public subsidies for driving and road infrastructure are taken as a given, even as said infrastructure crumbles in disrepair.
Innovative transportation architecture can become a tool for change. The collaboration between Miller Dunwiddie and Kimley-Horn resulted in the Silver Ramp, which helps to elevate the experience of making multimodal travel choices. Its spaces show how taking a regional shuttle or public transit can actually be simpler, more efficient, and less stressful than many Midwesterners assumed. America needs more integrated airport transit options. Similar projects that expand car capacity should be required to also serve other modes of transit. We already know that we have the design and engineering professionals who can visualize a more sustainable, equitable, and urbane future—and then build it.
Projects like the Silver Ramp invite a near-future scenario in which transportation is no longer so car-dependent, whether out of cultural change or climate necessity. If and when that happens, Midwestern urban regions will change too, likely becoming denser and more clustered. In that future, travel to the airport might become far easier—with more options and, maybe, fewer ramps.
Frank Edgerton Martin is a landscape historian, architectural writer, and design journalist.
Bruce N. Wright, FAIA is an architect and writer whose writings and technical expertise have contributed to the profession’s understanding of emerging materials and industrial fabrics.