Just as the U.S. auto industry underestimated the threat of Japaneseimports 20 years ago, the entire global auto industry may be under-estimating demands for "greener" and more socially responsiblevehicles, according to Dan Sperling, director of the Institute for Transportation Studies at UC Davis. Despite petroleum supply problems, air pollution and global warming, the conventional wisdom holds that the automobile and its petroleum-powered internal combustion engine are here to stay. "If the auto industry is not responsive to consumer demands, the government will intervene, as it has in California, in mandating the sale of zero-emission vehicles," Sperling says. "It is not the survival of the automobile itself that is at stake, but the survival of individual companies." Evidence suggests that the car has a strong future in some form. Efforts to reduce auto travel worldwide have been difficult, expensive and almost uniformly unsuccessful. Automobiles already account for most travel in developed countries. Even in Japan -- where distances are short, congestion is stifling and rail transit is superb -- autos account for nearly 60 percent of total travel and are increasing their market share quickly. Since cars are embedded in our way of life, Sperling says, the smartest strategy for reducing pollution is to make the vehicles more environmentally benign and less consuming of road space.