This brief is the sixteenth 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.

The intent of this sixteenth brief of Commuting in America is to assess what findings from the current research merit attention now and going forward. A central concern in interpreting commuting trends is the major challenge of discriminating between cydclical effects that are a product of the present state of the economy and those that are longer-term structural changes.