This article hints at the connection between sprawl and pedestrian deaths:
Even though much of Houston and surrounding areas have been swallowed by urban sprawl, sidewalk construction and road improvements have not kept pace — a trend that may have cost two pedestrians their lives this month....Both country-like streets have only one lane in each direction and for decades have lacked sidewalks.Several studies have confirmed that as sprawl increases, walking becomes more dangerous. With a couple of exceptions, dense cities have a much lower pedestrian fatality rate than sprawling areas like suburban Atlanta and Phoenix. And of course, the nature of sprawl pretty much requires people to drive everywhere, which means they're far more likely to die in car accidents than city dwellers.
In his landmark study Mortality Risk Associated With Leaving Home: Recognizing the Relevance of the Built Environment, William H. Lucy "analyzed city, county, state, and federal data for traffic fatalities and homicides by strangers for 15 metropolitan areas, and classified deaths as occurring in the central city, in inner suburbs, or in outer suburbs (exurbs)." After studying fifteen years' worth of data, Lucy concluded that
Traffic fatality rates were highest in exurban areas. Combined traffic fatality and homicide-by-stranger rates were higher in some or all outer counties than in central cities or inner suburbs in all of the metropolitan areas studied.There are, unfortunately, health costs associated with not being a pedestrian; other studies have shown a clear correlation between increased sprawl, and increased hypertension and body weight.
That said, I'll leave you with a thought-provoking response to Houston's latest pedestrian deaths from Guy Hagstette, Mayor Bill White's special assistant for urban design:
"There wasn't even an anticipation there were people at all who would want to walk in those areas."