Safe Urban Form: Revisiting the Relationship Between Community Design and Traffic Safety

By Eric Dumbaugh and Robert Rae
Dallas, TX (January 1, 2009)- This recent research reinforces many of the safety assumptions embedded in contemporary community design practice are not substantiated by the empirical evidence. 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.


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.
In fact, the research found that 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.
Moreover, they found intersections to have mixed effects on crash incidence, and concluded that the better focus for improving traffic safety is to focus on vehicle operating speeds and systematic design error. Finally, they propose three community design strategies that may help improve traffic safety.
Related Resources:
Journal of American Planning Association- Safe Urban Form: Revisiting the Relationship Between Community Design and Traffic Safety (PDF)
Safe Urban Form (PPT)