Winner of the 2009 Best Article Award: Journal of the American Planning Association

Press release

Safe Urban Form: Revisiting the Relationship Between Community Design and Traffic Safety
Eric Dumbaugh and Robert Rae
Volume 75, issue 3, 2009

The judges decided that Dumbaugh and Rae shatter myths about the safety of suburban road design and associated community design. Their paper is an excellent piece of research that reinforces the notion of evidence-based design. The authors focus on a critical issue associated with urban design, the research design is well-conceived, the statistical analysis is rigorous, and the implications to the practice of urban design are powerful.

Results and conclusions: We find that many of the safety assumptions embedded in contemporary community design practice are not substantiated by the empirical evidence. While disconnecting local street networks and relocating nonresidential uses to arterial thoroughfares can reduce neighborhood traffic volumes, this does not appear to improve safety, but rather substitutes one set of safety problems for another. We found urban arterials, arterial-oriented commercial developments, and big box stores to be associated with increased incidences of traffic-related crashes and injuries, while higher-density communities with more traditional, pedestrian-scaled retail configurations were associated with fewer crashes. We found intersections to have mixed effects on crash incidence. We conclude by discussing the likely reasons for these findings (vehicle operating speeds and systematic design error) and outline three community design strategies that may help improve traffic safety.