This brief is the fifteenth in a series of briefs that constitute a body of knowledge describing commuting in America. This body of work, sponsored by American Association of State Highway and Transportation Officials (AASHTO) and carried out in conjunction with a National Cooperative Highway Research Program (NCHRP) project that provided supporting data, builds on three prior Commuting in America documents that were issued over the past three decades. Brief 15 describes the pattern of commuting travel. Specifically, the home-to-work trip is analyzed to understand the flow of travel that has to be accommodated by transportation infrastructure and services. The discussion covers two distinct elements: first, information about the length of commute trips; and second, information about the spatial orientation of trip flows.