Ewing 2002 - "Measuring Sprawl and Its Impact"

Ewing, Reid; Pendall, Rolf; Chen, Don
"Measuring Sprawl and Its Impact"
Smart Growth America
2002
On the Web
Relevance: high

Ewing et al. created a sprawl index for ~83 metropolitan areas, incorporating density, land use mix, centeredness, and street accessibility. The authors also estimated the impact of sprawl on various transportation-related outcomes. They found that a higher degree of sprawl is associated with higher average vehicle ownership, daily VMT per capita, annual traffic fatality rate, and maximum ozone level; more sprawl was associated with a lower share of work trips by transit and walking. Note that, as with most sprawl studies, we can't assume a causal relationship.

The authors also tested how individual sprawl factors affect transportation outcomes. The density factor of the sprawl index had the strongest relationship, followed by the centeredness factor.  Land use mix and street accessibility were barely significant, perhaps because of

The report contains the sprawl index and the coefficients of sprawl's impact on the transportation outcomes, so one could estimate how many fewer fatalities Seattle (100.9) would have if it were as compact as Portland (126.0).