Motorization is accelerating even more rapidly in cities. Personal vehicles, from scooters to large company cars, are improving access to goods, services, and activities, including an expanded array of job and educational opportunities. They provide unmatched flexibility, convenience, and freedom. For many individuals, vehicles are desirable as a
secure and private means of travel, and as status symbols. For businesses, they are a means of increasing productivity.
But personal motorization also imposes enormous costs, especially in cities. The well-known litany includes air and noise pollution, neighborhood fragmentation, and high energy use. Motorized transport is the largest consumer of the world’s petroleum, making it central to international concerns over energy security and political stability in volatile
regions. China is now the second largest importer of oil in the world, although its vehicle ownership rates are but one-fiftieth of the US’s. The developing world is an increasing source of greenhouse gas (GHG) emissions, which are rising faster in transportation than in any other sector.