clock menu more-arrow no yes mobile

Filed under:

Now this is how you design a freeway underpass

New, 5 comments

A California city turns a dark tunnel into an inviting walkway

The East Campbell Avenue Portals opened this week
City of Campbell

Like most places in the U.S., the Silicon Valley city of Campbell made a big mistake a half-century ago. When California State Route 17 came plowing through town, transportation planners located it so close to Campbell’s historic downtown that it sheared the picturesque streets off from the surrounding neighborhoods. This was fine for cars, and awful for everyone else, who now had to duck into a dark, dirty, dangerous hole. This week, a smart redesign of Campbell’s busiest underpass revealed a well-lit path fringed with public art, landscaping, and a sweeping 26-foot-wide sidewalk.

While the East Campbell Avenue Portals may look like a simple infrastructural makeover, the key is in the execution. Nearly all the space in the underpass was devoted to vehicles, with a narrow 4-foot sidewalk—added almost as an afterthought—traveling far too close to fast-moving cars. There just wasn’t enough room to keep cars moving and give pedestrians more space. So engineers got creative.

The “before” shot, looking a lot like most freeway underpasses do today
City of Campbell

The design uses the existing structural framework to keep key girders in place, then carves out more space for pedestrians, excavating 4,700 cubic yards of dirt from the sides. A second retaining wall creates a stunning 11,000 square feet of space for walkers to travel beneath the freeway. Lighting, artwork by Susan Zoccola that depicts locally grown produce, and wayfinding was also added, and new bike lanes now clearly demarcate the roadway.

The portal cost about $4.85 million, funded mostly through grants, and even though it was delayed due to a redesign, the entire project was finished in less than two years. It took about five years prior to that to study, design, and approve the project. But the good thing is that because it improves upon a standard Caltrans underpass design, it could be easily deployed anywhere else in California—or beyond.

The portals create a pleasant entryway to downtown Campbell.
City of Campbell

One feature that’s not easy to see from the image is the addition of a wall that completely separates walkers from bikers and drivers. This creates a quiet, protected stroll, but one concern that I had was that the wall made the pedestrian walkway almost too isolated, and might create spaces that would encourage unsafe behavior. But the city’s senior civil engineer Fred Ho assured me that the portals use bright LED lights and cameras at night, and see a lot of natural light during the day. “The tunnel effect appears worse when viewing the portals from the outside,” he said. “The openings of the pedestrian portals being 26 feet wide and 15 feet high actually let in a good amount of light.”

Freeway cap parks—or removing freeways entirely—have become increasingly popular as cities seek to repair the damage inflicted by urban freeways. But capping or “decking” a freeway is expensive, which is why other alternatives need to be explored—including adapting the particular infrastructural eccentricities of highways for public space, as our own Karrie Jacobs explored through Houston’s Buffalo Bayou project. Cities like Miami are turning the undersides of their transit underpasses into linear parks.

The James Corner Field Operations-designed Underline for beneath Miami’s MetroRail
James Corner Field Operations

Maybe solutions can be even simpler than that. In Vancouver, a simple public art piece plays upon the cavernous space below the Granville Bridge. Local artist Rodney Graham designed a giant, glittery LED-lit chandelier (not crystal, don’t worry) which will spin and illuminate, providing both spectacle and lighting for pedestrians. It’s being paid for by a developer building the Bjarke Ingels-designed tower nearby, and was just approved by the city’s council.

Rodney Graham’s LED-lit chandelier would connect a new Vancouver tower to its surrounding neighborhood.
Westbank Corporation

These types of low-cost, high-impact solutions to reconnect neighborhoods severed by highways are part of the USDOT’s new Every Place Counts Design Challenge, itself part of the larger Ladders of Opportunity campaign to address inequality. Last month, Secretary of Transportation Anthony Foxx visited four U.S. cities—Spokane, Nashville, Philadelphia, and Minneapolis-St. Paul—which held design workshops in partnership with the Center for New Urbanism focusing on fixing particularly harrowing freeway crossings.

An “island” over I-94 was proposed at the St. Paul workshop.
Nate Hood and Eric Orozco

For each solution, an important indicator of success seemed to be using existing infrastructure in an unexpected way. As the St. Paul facilitator Nathaniel Hood told Next City, their team looked at more than just automobile crossings to reconnect the severed Rondo community. One concept used an old railroad bridge for pedestrian access, creating the base for what’s really just a glorified median that might host a tech incubator.

In many cases cities don't have the time or the capital to bury a freeway a la Boston’s Big Dig. They need to be innovative with what assets they have. As these examples show, there’s no one way to cross—and reconnect—a highway.