The built environment and the incidence of pedestrian and cyclist crashes

This study applied negative binomial regressions to understand how the characteristics of the built environment may affect the incidence of crashes involving pedestrians and cyclists. Arterial thoroughfares, big box stores and strip commercial uses were all associated with increased risk for pedestrians and cyclists alike. Unlike earlier studies on pedestrian and cyclist crash risk, however, this study hypothesized that it was the configuration of commercial and retail uses that mattered, rather than the uses themselves. To test this, this study included a variable indicating the number of pedestrian-scaled retail uses in a community in the models. Indeed, while strip commercial uses and big box stores were a safety problem, this variable had a negative, though statistically insignificant, effect on crash incidence, suggesting that road users were modifying their behavior in these environments in a manner that prevented these crashes from occurring. Further, although earlier studies have asserted that population density was a risk factor for pedestrians and cyclists, this study found it to have a positive but weak effect on total pedestrian crashes, and no statistically meaningful effect on pedestrian killed or severely injured (KSI) crashes, nor on total or KSI crashes involving cyclists. Finally, this study found that whereas four-leg intersections were associated with increased numbers of pedestrian and cyclist crashes, three-leg intersections had no effect, or even a negative effect on crash incidence involving pedestrians and cyclists. This finding suggests that three-leg intersections may be a desirable means for increasing local street connectivity for pedestrians and cyclists without simultaneously increasing their exposure to traffic related crashes, injuries or deaths.