Scientists are trying to some small cars that may someday take the place of today's big automobiles. If everyone drives such cars in the future, there will be less in the air. There will also be more space for parking cars in cities, and the streets will be less . The little cars will cost much less to and to drive. Driving will be safer, too, as these little cars can go only 65 kilometres per hour. The little cars will be fine for getting around the city, but they will not be for long trips. Little cars which are powered by gasoline will go 450 kilometers before needing to stop for more gasoline.