Longitudinal socioeconomic and built environment shifts in US bicyclist fatality locations 2001–2020

Combining longitudinal scatterplots, a longitudinal hierarchical negative binomial regression, and spatial analyses, we analyzed United States (US) bicyclist fatality data on the census tract level to understand how the built environment and socioeconomic characteristics of bicyclist fatality locations shifted between 2001 and 2020. Results indicate that while bicyclist fatalities largely occurred in urbanized areas in both the before (2001-2010) and after (2011-2020) periods, they trended toward lower-density suburban areas during the after period. The population density of census tracts that experienced a bicyclist fatality decreased 22.3% from the before to after periods and intersection density decreased 11.1%. This novel finding contributes additional context regarding the urban environments in which bicyclists experience the most severe safety outcomes, encouraging focus beyond the traditional urban core and downtown areas. Relative to the national average, census tracts that experienced a bicyclist fatality had lower proportions of White non-Hispanic residents, higher proportions of residents living in poverty, and lower proportions of residents with bachelor’s degrees, with all those relationships being significant at 95% confidence and becoming stronger over the study period. These findings provide further insight to guide practitioners and policymakers in determining where safe and connected bicycle networks should be prioritized at the regional level and in suburban contexts, as well as which neighborhoods and populations may warrant the greatest focus for such interventions.