| Assuming that a constant travel-time
budget, geographic constraints and short-term infrastructure constraints persist
as fundamental features of global mobility, what long-term results can one
expect? In high-income regions, {{U}}(41) {{/U}} North America, our
picture suggests that the share of traffic {{U}}(42) {{/U}} supplied by
buses and automobiles will decline as high-speed transport rises sharply. In
developing countries, we {{U}}(43) {{/U}} the strongest increase to be
in the shares first for buses and later for automobiles. Globally, these
{{U}}(44) {{/U}} in bus and automobile transport are partially
offsetting. In all regions, the share of lowspeed mil transport will probably
continue its strongly {{U}}(45) {{/U}} decline. We expect that throughout the period 1990～2050, the {{U}}(46) {{/U}} North American will continue to devote most of his or her 1.1-hour travel-time {{U}}(47) {{/U}} to automobile travel. The very large demand {{U}}(48) {{/U}} air travel (or high-speed mil travel) that will be manifest in 2050 {{U}}(49) {{/U}} to only 12 minutes per person a day; a little time goes a long way in the air. In several developing regions, most travel {{U}}(50) {{/U}} in 2050 will still be devoted to nonmotorized modes. Buses will persist {{U}}(51) {{/U}} the primary form of motorized transportation in developing countries for decades.{{U}} (52) {{/U}} important air travel becomes, buses, automobiles and {{U}}(53) {{/U}} lowspeed trains will surely go on serving vital functions.{{U}} (54) {{/U}} of the super-rich already commute and shop in aircraft, but average people will continue to spend most of their travel time on the {{U}}(55) {{/U}}. |