Ewing 2003 - "Urban Sprawl as a Risk Factor in Motor Vehicle Occupant and Pedestrian Fatalities"

Ewing, Reid, PhD; Richard A. Scheiber; Charles v. Zegeer
“Urban Sprawl as a Risk Factor in Motor Vehicle Occupant and Pedestrian Fatalities”
American Journal of Public Health
September 2003; v93, n.9; pp 1541-1545.
On the web
Relevance: High

The authors created a sprawl index for 448 US Counties in the largest 101 metropolitan areas.  For every 1% increase in the index (i.e. more compact, less sprawl), all-mode traffic fatality rates fell by 1.49% and pedestrian fatality rates fell by 1.47% to 3.56%, after adjusting for pedestrian exposure. In short, places that sprawled more had higher death rates from traffic accidents.

In short -- people who live in more sprawling metropolitan counties were more likely to die in car accidents.

  • Although only about 5% of all trips are made on foot, pedestrian fatalities make up about 12% of all traffic deaths, making walking one of the most dangerous modes of travel.
  • We recognize that the fatality data studied are based on the location of a crash, whereas the population density and street accessibility data are based on place of residence, which may be different. Because most commuters who cross county borders live in lower-density -bedroom communities and work in higher-density central areas, the traffic fatality rate in urban counties would be inflated relative to the population living there.
  • Sprawling areas tend to have wide, long streets that encourage excessive speed. A pedestrian struck by a motor vehicle traveling at 40 mph has an 85% change of being killed, compared with a 45% change of death as 30 mph and a 5% chance at 20 mph.
  • Subsequent studies should investigate relationships at a finer geographic scale and should strive to improve on the measure of exposure used to adjust pedestrian fatality rates.


The comments to this entry are closed.