The last decades of the twentieth century witnessed the transforming processes of metropolitan economic restructuring (e.g., flexible production, growth of information and telecommunication technologies) along with social changes that have been created by and, in turn, propel that restructuring. These forces have had considerable impacts on urban transportation systems. The twenty-first century will undoubtedly see a variety of new social and technological trends that will continue to influence the ways in which transport and communication systems are supplied and utilized. Although at the present time a wide range of speculation exists about future transport systems, two trends that are apparent are increasing vehicle size and fuel consump...