Automated Traffic Control Systems

Historically, traffic control for all modes of transportation took a number of forms, all of them relatively informal, to avoid collisions or to ensure that certain vessels or vehicles had the right of way. Even before the Industrial Revolution the growth of population and traffic in cities made traveling in the streets a dangerous proposition. As a result, in London in 1868 an experiment was performed in which a lantern was used as a signal to let horse-drawn carriages know when to stop and when to go ahead. Initially, the traffic signal was successful. However, early the next year the gas line connected to the lantern ruptured, creating an explosion that killed the policeman operating the signal.

As busy as traffic had seemed with the proliferation of horse carts and carriages, the congestion and danger dramatically increased with the appearance of automobiles. Automobiles not only increased the number of vehicles in the street but, because of their speed and noise, increased the danger to drivers and pedestrians.

By 1912, the idea of using a traffic light to control who would go and who would wait at intersections seemed to be worth revisiting. In that year a traffic signal lamp was installed in Salt Lake City, Utah. Two years later a traffic light was installed in Cleveland, Ohio; the lantern was operated automatically but the controls could be overridden by police at the neighboring station.

The increased number of vehicles and drivers did nothing to increase caution on the part of those who actually drove the new machines. Accidents with horse-drawn vehicles or with other automobiles were all too frequent. The possibilities of a fatal crash with a train were not yet absorbed by drivers. As late as the mid-1920s, in an area as sophisticated as the region around New York City, accidents as the result of automobiles crossing railroad tracks when trains were running were fairly common. By this time, state and local governments as well as the federal government were concerned with rising fatalities and were beginning to take measures to establish traffic control systems that would move increasingly from those operated on the spot by individuals to those operated in an automated fashion.