PEDESTRIAN BRIDGES

Communities everywhere are championing bridges designed for the sole enjoyment of those on foot or on wheels. A genre of their own, pedestrian crossings have influenced how designers, municipalities, and citizens think about bridges both large and small, expanding the conversation about connectivity and its enabling infrastructure.

Usually located in metropolitan centers, where the need for outdoor recreational areas is greatest, pedestrian bridges highlight what’s special about their locations, connecting neighborhoods and, more important, the people who live in them. They have been used to call attention to historical or cultural districts, to revitalize neglected neighborhoods, and to create instant landmarks in new developments. A potent means of place making, they can transform a community’s identity.

Their human scale, exuberant designs, dramatic lighting, and invitation to slow down and revel in one’s surroundings are a welcome change of pace in a rushed world. Benches, observation platforms, and wayfaring signage boost that sense of tranquility. Intended to be touched, experienced slowly, and viewed at close range, the finishes and detailing of footbridges are finer than those of vehicular bridges.

“Pedestrian bridges have long led a marginal existence and we have only gradually become aware that they could be more than purely functional structures. ”

—ANDREAS KEIL, PEDESTRIAN BRIDGES, 2013

These multidisciplinary projects catalyze the imagination as well as the spirit of collaboration, bringing together civil engineers, architects, artists, landscape designers, and lighting experts—as well as visionary clients, planners, and contractors.

Liberated from many of the scale and budget parameters that govern vehicular and rail bridges, they challenge convention. Structurally too there are important differences; most critical are the kinds of loads they carry: traffic loads generated by people are far less punishing than those that include trucks. However, given uneven, sometimes heavy foot traffic, designers must anticipate their dynamic behavior, with critical lessons learned about walker-induced vibrations from London’s Millennium Bridge (see here).

Most pedestrian bridges are environmentally responsible, with efficient structures, lighting systems, and solar panels that help reduce their carbon footprint. Above all, their inspired settings and inventive designs encourage people to walk or cycle, and leave their cars at home.

A tenet of sustainability is making use of what is already at hand. Unused bridges also are being reclaimed for public enjoyment. In Poughkeepsie, New York, a nineteenth-century rail link that had been abandoned for decades reopened as a pedestrian bridge in 2009. Renamed Walkway Over the Hudson, and now a New York State Historic Park, the bridge stands 212 feet (65 meters) above the Hudson River, providing stunning panoramic views up and down the 1.3-mile (2.1-kilometer) span. Similarly, plans are afoot to repurpose an aging bridge in Washington, D.C. Once completed, the 11th Street Bridge Park across the Anacostia River will include gallery and performance spaces, playgrounds, a café, a boat launch, and, incidentally, a river crossing as well.

Built for the public good, pedestrian bridges increasingly address the social good. Taking advantage of the public’s slower pace and increased receptivity to the natural beauty that surrounds them, footbridges provide many teachable moments. In the face of global warming, some bridges address the water itself—its sensitive ecosystems as well as its changing levels. Room for the River, a national initiative in the Netherlands, gives rivers room to flood safely at more than thirty locations, while creating new public parks and drawing attention to climate change; the Citadel Bridge, shown on here, is part of that innovative program. And Bridges to Prosperity (see here), a nonprofit organization, builds footbridges for communities whose lives literally depend on them.

Calgary’s George C. King Bridge (2014) fuses three slender arches that cross the Bow River lightly, like stones skipped across water. Designed by architect RFR and engineer WSP, the 597-foot (182-meter) steel span meets the challenges posed by the swift current and ice buildup that could be as much as 10 feet (3.0 meters) thick. Balustrade lighting eliminated the need for visually disruptive light poles. Soft below-deck lighting illuminates the river.

The Citadel Bridge (2015) in Nijmegen is part of the Netherlands’ Room for the River program. Designed by NEXT Architects, the 700-foot (213-meter)-long bridge sits in a floodplain that is partially submerged a few days every year. Those fluvial dynamics drove the bridge’s design; at high tide, the lowest part of the bridge is underwater. Stepping stones that double as benches reinforce awareness of the changing water levels.