May 1, 2006
Streetless in Seattle
An innovative shared-space design is taking shape in the city’s developing South Lake Union neighborhood.
At Pike Place Market in Seattle, the fish-throwing vendors aren’t the only sign of barely contained chaos. Crowds of pedestrians also mingle alongside cars and trucks, creating a jumbled vibrant street scene at Pike Place and Post Alley. “The great thing about the market is nobody planned it,” says Lesley Bain, a partner at Weinstein AU, a Seattle architecture and urban-design firm. “You have a spontaneous overflow of people into the street.”
Bain has a professional interest in serendipity. She is the lead consultant on an innovative streetscape in South Lake Union, an emerging high-density neighborhood just a half mile north of the market. The Terry Avenue North street-design guidelines, which cover a six-block stretch linking downtown to Lake Union, radically depart from the standard American approach to traffic design. Instead of segregating vehicles and pedestrians, the project aims to encourage people to share a single travel lane with slow-moving cars. “We’re breaking some conventions here,” says Lyle Bicknell, the city’s urban-design project manager for Terry Avenue North.
Bankrolled by Microsoft cofounder Paul Allen and his company, Vulcan, the once languishing industrial district is evolving into a world-class mixed-use biotechnology hub. Several large infrastructure projects, including a glittering new lakeside park and streetcar line, will anchor the office buildings, condos, and pharmaceutical labs springing up on the 60-plus acres Vulcan has acquired over the past 10 years. The original charter for Terry Avenue—the neighborhood’s key north-south pedestrian corridor and gateway to the new park—called for a woonerf, a curbless street first introduced in the Netherlands in the 1970s. Although the term refers technically to residential streets, woonerfs have also become synonymous with a larger European planning trend called “shared space.” Both utopian and pragmatic, the approach redefines streets as public places for people instead of single-purpose conduits for automobiles. “The reason the Dutch invented the woonerf concept is because the Netherlands has the highest population density in the world,” Bicknell says. “No space can serve just a single function. Conversely, in the United States we’ve perfected the art of getting two acres to do the work of one.”
Holland is no longer the only example of the shared-space phenomenon. In Denmark, Great Britain, Spain, and Sweden, communities are also eliminating curbs, traffic signals, and road markings, and allowing cars, bikes, and pedestrians to intermingle organically. The concept is spreading so rapidly that last year the Congress for the New Urbanism identified shared space as “the biggest recent innovation in European street design.” Studies show that the physical design of shared streets slows traffic and can actually be safer for pedestrians than conventional street design.
Terry Avenue North aligned with the shared-street concept in several ways. It has an unusually wide right of way, varying from 71 to 76 feet, and its multiuse past is visible in embedded Burlington-Northern rail tracks and the original brick surface. Many sections of the street have no sidewalks, and parked cars and loading trucks often jut into the public right-of-way. “If you look at old pictures of any city, you see horse carts and people and streetcars, all in this great richness,” Bicknell says. “We’ve gotten very good at segregating out all the forms of transportation. Terry Avenue offered an opportunity to not do that.” Though Seattle Department of Transportation director Grace Crunican originally issued the directive for a woonerf, Vulcan was quick to support it, believing the design would help create an identity for the neighborhood. “We liked the idea of inviting people to cross in the middle of the street,” says Sharon Coleman, Vulcan’s real estate development manager. “It gives the street a unique character.”
But as the Terry Avenue project team discovered, Seattle is no Amsterdam. A pervasive risk-management climate, as well as new federal accessibility guidelines, stymied efforts to incorporate all the elements associated with the shared-space model. “The number-one challenge was the ADA [Americans with Disabilities Act],” says Ron Scharf, transportation project manager for Terry Avenue North. “You cannot build a true woonerf given the criteria of the federal government on safety and accessibility.”
The modified Terry Avenue North guidelines were adopted into Seattle’s design manual last year and will be implemented as development occurs. Two key principles guided the design team: visual continuity linking pedestrian and car zones, and a lateral rather than linear approach to how people will use the street. “You’re not walking along a channelized conduit for people alongside a channelized conduit for vehicles,” says landscape architect Shannon Nichol, founding partner of Gustafson Guthrie Nichol and a consultant on Terry Avenue North. “You’re walking through a series of spaces that extend across the whole width of the street.”
Continuous brick or concrete pavers will help define the entire street as pedestrian friendly. Instead of the kinds of evenly spaced trees that traditionally line streets (Bain calls them “lollipop trees”), stand-alone native canopy trees such as Douglas fir and western red cedar will act as grand focal points. Angled parking, creeping ground cover, and the streetcar will reinforce an atmosphere of eclectic disorder. In keeping with a traditional woonerf, Terry Avenue won’t have any traffic lights. But ADA regulations requiring separation between car-free and car-accessible zones did force a major concession: curbs and tactile warning strips for the visually impaired had to be added. “This runs absolutely contrary to having a seamless plane of undifferentiated material,” Bicknell says, adding that the unusual collaboration between the project’s traffic engineers and urban designers did mitigate some of the ADA’s impact. The final guidelines include a low two-inch curb along the east side of the street and white warning strips instead of the standard bright yellow.
Is Terry Avenue North a harbinger of the future in the United States? It may be too early to tell. Dave Yanchulis, spokesperson for the Access Board, a federal agency responsible for developing accessible design criteria, says a new draft of public right-of-way guidelines will not address shared-space design trends. “It’s on our radar, but it is not considered [something that is] happening in the United States,” he says. Nevertheless, Seattle’s local planners are undeterred. A second woonerf is in the works for a new Four Seasons hotel and condo complex next to the Pike Place Market. The half-block shared street will capitalize on the mix of pedestrians and cars associated with a hotel drop-off zone. “I’m a big fan of mixing autos and people,” says NBBJ’s Bill Bain, architect of the Four Seasons. “Although when you say that, most people think you’re crazy.”