At the close of the year 1900, motor vehicle registrations throughout the United States totaled 8000. These vehicles rode on unpaved and often dusty country roads. The only problem of traffic was an occasional pedestrian or a frightened horse or cow frenzied by the roar of this new creature. Today more than 82,000,000 registrations, representing 50% of the world's automobiles, are recorded in this country. In 1963 these vehicles traveled 798 billion...