“…Onega et al 2008Onega et al , 2010aOnega et al , 2010bOnega et al , 2011Onega, Duell, Shi, Demidenko, Gottlieb, et al 2009;Celaya et al 2010). Berke and Shi (2009) found that when simply using geometric centroids of zip code polygons, which was adopted by many health-care studies, the error of the estimated average travel time can go above 10%; when more detailed population data are incorporated, the average error can go below 3%. With RCMC, rather than using centroids (however defined) or service area belts to measure aggregate travel distance or travel time, one can make individual measurements based on the disaggregated locations, which avoids the imprecision problem and its consequences.…”