For a consortium of major U.S., European and Japanese auto manufacturers and related firms under the auspices of the World Business Council, members of The Brattle Group played a key role in a major investigation of long-term trends in mobility. This study was worldwide in scope, addressing urban, rural, and intercity passenger and freight transportation in both developed and developing countries. The study focused on the sustainability of the current transportation system and the extent to which exhaustion of fossil fuels, environmental constraints, infrastructure shortages, or institutional barriers were likely to constrain mobility over the next several decades. Results of this work had a significant impact on the long-term business and product development strategies of the study’s sponsors.