Dr. Zane Hellmann - Best of the Best in Pediatric Surgery 2025

The National Walk Index was formulated by the Environmental Protection Agency using measures of the built environment to determine the likelihood for walking trips in a given area.

The walkability index takes into account aspects of intersection density, transit stop proximity and employment and housing mix to create a score for walkability within a community.

The fatality analysis reporting system FARS is a nationwide data set maintained by the US Department of Transportation and captures data from all motor vehicle collisions in the United States resulting in a fatality within 30 days.

The social vulnerability index has been shown to correlate with overall trauma fatality rates by county.

158 counties in 40 states were included in the study.

Median average child population was 177,000, median walkability score was 11.4.

Average mortality rate for included counties was 1.82 deaths per 100,000 children.

There was no relationship between county child population and mortality rates.

Each decile increase in walkability was associated with a 7% decrease in mortality rate when controlling for both social vulnerability and population density.

Each decile increase in walkability was associated with an 8% decrease in mortality for children who were occupants of motor vehicles.

For counties in the top half of vulnerability, there is a 9% decrease in mortality rate for each decile increase in walkability.

Counties in the top decile for walkability had half the mortality rate of counties in the bottom decile, even when controlling for county level vulnerability and population density.

The fatality reporting system does not provide insight into the likelihood of non fatal motor vehicle collisions.

Counties were limited to those with at least 100,000 children to improve the stability of analyzed fatality rates, which limits application to less populous counties that tend to be less walkable and more rural.

The Social Vulnerability Index was chosen because it is geared towards county level work, whereas the ADI is more local in its measured effects.

The research team is now looking at more granular interventions such as active school zones or increased crosswalks to see if they affect both motor vehicle trauma and pedestrian trauma.