This brief is the ninth in a series of sixteen 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 9 provides information on how the commute trip influences the overall pattern of travel. Part of the importance of commuting is that commuting travel influences the travel patterns of commuters for non-commute purposes. Additionally, the travel patterns of non-commuters are affected as they plan their travel in response to the times and locations of heavy travel by commuters.