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a Cumulative distribution functions of actual, closest, and differential drive time. b Cumulative distribution functions of differential drive times by covariates. I Rural/urban status. II Ethnicity. a
Closest. 
Actual. 
Differential. bI
Large rural town. Small town/isolated rural. 
Sub-urban. Urban core. bII
White, non-Hispanic. Black, non-Hispanic. Hispanic. Asian. 
Native American. 
Other
