Do Stapleton neighborhood's wide streets make traffic more dangerous?
A new study of the Stapleton neighborhood, Denver's nationally acclaimed infill project, concludes that key traffic engineering decisions have encouraged high-speed driving rather than traffic "calming," made residential areas less safe and generally worked against efforts to develop the area as a showcase of New Urbanism -- a design ethos that emphasizes walkability, bike and transit use, and community-oriented development.
"If we have streets in a New Urbanist neighborhood where it's possible for drivers to go fifty, sixty or seventy miles per hour, then we've done something wrong," concludes study author Wesley Marshall, an assistant professor of civil engineering at the University of Colorado Denver.
Marshall's study, published this spring in the Journal of Urbanism: International Research on Placemaking and Urban Sustainability, looks at how well the transformation of the former airport into a community of more than 14,000 residents has delivered on certain New Urbanism goals, including compact, walkable and safe streets. (A brief abstract of the study is available online.) While Stapleton has been celebrated among urban planners as one of the largest and most successful infill projects of its kind, offering ample open space and bike trails, Marshall contends that a "conventional traffic engineering mindset" has compromised the design and promoted heavier and higher speed auto use.
Part of Stapleton's problem, in Marshall's view, is a lack of overall connectivity: "While a handful of streets connect Stapleton to the surrounding neighborhoods to the east and south, there are very few streets connecting one end of Stapleton to the other." The major traffic flow is directed to two arterials -- Martin Luther King Boulevard for east-west traffic, Central Park Boulevard for north-south -- that run through the heart of the development, rather than on its periphery, as is the case with some New Urban designs.
The generous width of the streets is another concern. MLK and CPB were built with future demand in mind, but their seeming emptiness at present encourages higher speeds; about one-fifth or the motorists on either parkway at any given time are exceeding the speed limit, sometimes achieving highway speeds. The problem with leadfooted test pilots is even worse on feeder streets such as Beeler, which fronts against blocks of open space popular with families and cyclists; measurements taken there indicate that more than 63 percent of the drivers are speeding, "with some vehicles surpassing fifty mph."
New Urbanism proponents like to push the advantages of narrow streets, which tend to slow down traffic. In many places, Stapleton's designers opted instead for parking lanes, figuring that a row of parked cars would slow down traffic just as well. But those spaces are under-utilized, Marshall notes, because so many residences have garages or off-street parking -- leading once again to higher speeds and more crashes.
Even more intriguing, Marshall found that supposedly transit-oriented infill developments such as Stapleton and Lowry are lagging behind older, established neighborhoods -- Cherry Creek, Highlands and East Colfax, specifically -- in terms of the number of residents choosing to walk, bike or use public transit rather than drive. Marshall suggests several possible reasons for Stapleton's reliance on cars, including the tendency to concentrate commercial and retail services into certain "zones" in the new developments, while they're more spread out and accessible in older areas.
He may be onto something there; residents on Stapleton's east side have been increasingly vocal about the how the proposed Eastbridge Town Center, which was supposed to be a small-scale community retail center, has morphed into another King Soopers with a giant parking lot, similar to the shopping center anchoring the west side of Stapleton at Quebec. Neighbors fear the regional store will draw more traffic into the neighborhood even as they compel those who wanted something different at Eastbridge to drive further to find more options.
Marshall observes that the problems at Stapleton aren't unfixable, but "the difficulty is that such changes are difficult to implement, both politically and economically, after a community has already been built." He reports that one Beeler Street resident has already acted to narrow the street and slow traffic by parking vehicles on either side, a few feet from the curb, and displaying a sign that reads: "Drive like your kids live here."
More from our Media archive circa June 2010: "Stapleton neighborhood fighting sloth, obesity epidemic, says NPR."