How many new urbanist neighborhoods are truly safe for walking?

It's become a common refrain in new urbanist presentations: Suburban subdivisions—clotted with cul-de-sacs, reliant on just a few major roads for through traffic—are perilous.

The argument, as typically made, is that in the absence of numerous narrow through streets, people end up being exposed to too much fast traffic on the major thoroughfares serving the suburbs.

But on the Colorado public radio show Colorado Matters, discussion of safety in residential areas took a different twist this week: It cited Stapleton, Colorado's largest and best-known new urbanist development, as a place where walking is hazardous. Who's have thought it?

Reporter Zachary Barr accompanied Stapleton resident Sophia Briegleb as she walked her six-year-old son Alex to his school three-quarters of a mile away. "Sophia says she chose the neighborhood because it's walkable," Barr observed.  And indeed, conditions genuinely are safe for walking—not to mention biking—on 35th Avenue, a street that "has no outlet so it's used just by people who live in Stapleton," the reporter noted.

But then mother and son arrived at busy Central Park Boulevard, a wide road whose "walk" signal lasts barely long enough for children to get to the other side of the pavement before traffic comes speeding throough. The station reminded listeners of an accident in which a motorist struck a pregnant woman at Central Park Boulevard and East 29th Aveue in Stapleton; the woman survived, but her unborn son died.

Barr then told of another Stapleton mother who, because Central Park Boulevard is so treacherous, walks her children several blocks out of their way, to a spot where one of them boards a bus to get to school. The woman does that rather than walk the child directly to the school itself, which is only eight blocks from her house.

The host of Colorado Matters, Ryan Warner, explained that this "is an example of how a quiet neighborhood can be really busy on its edges." He backed up that observation by introducing a thought from Wesley Marshall, a civil engineering professor at University of Colorado-Denver. Marshall is known in new urbanist circles for the research he's conducted with his former professor, the University of Connecticut's new urbanist transportation specialist Norman Garrick.

Marshall told the program that the layout at Stapleton "leads to more serious accidents." In Marshall's studies of traffic accident data, it turns out that neighborhoods like Stapleton's are more dangerous than "an old-fashioned north-south street grid, with lots of through streets."

That traffic safety is a problem at Stapleton came as a surprise to me, so I got in touch with Marshall. He replied by confirming that although Stapleton has some good internal streets, it does in fact become dangerous on its periphery. 

"One reason it is becoming an issue in Stapleton is because the dangerous roads are no longer on the edge of the community where it isn't as much of a public concern," Marshall explained. "This one runs right through the heart of Stapleton."

"Most New Urbanist developments wouldn't have run into this problem because of their relative size," Marshall elaborated. "However, Stapleton is large enough where these sorts of issues that haven't been addressed adequately yet in other examples are beginning to crop up."

Stapleton is not alone. There are other new urbanist developments with broad, dangerous roads on the edges, if not running through them. That flaw was evident at Kentlands, in Gaithersburg, Maryland, from the beginning. Kentlands streets mostly are narrow and very comfortable for walking and biking. But at the edge near the Rachel Carson School, a pedestrian encounters a broad road that separates Kentlands from its residential neighbors.

Larger-scale community planning needs more attention. Safe individual neighborhoods are not enough in themselves. Youngsters—and adults, some of whom are not spry—will inevitably want to reach destinations more than a few blocks away. As things now stand, they face serious obstacles, even at Stapleton, which was conceived as an alternative to conventional suburban development.

Marshall and the staff at Colorado Matters have, to their credit, brought a chronic problem to everyone's attention. The question, then, is: What will be done to make not just small neighborhoods but the larger terrain safe for people on foot or on bikes?

New urbanists cannot claim that safety is a problem only in conventionally designed subdivisions.

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