Traffic Control: The Need For Change As the population of the United States dramatically increases and the number of vehicles on the nation's roads and highways skyrockets, new methods of traffic control and organization have become necessary, by utilizing new methods of transportation or by revising the current system. In the past 15 years, the number of vehicles on American roads has increased 41.9%, the number of licensed drivers has increased 29.3%, but the size of the general population has only risen 15.9% (Clark 387-404). Between the years 1975 and 1985, the number of miles driven by Americans rose