Surveillance and Control of Tunnel Traffic by an On-Line Digital Computer.

An experimental surveillance and control system was in operation for one lane of the Lincoln Tunnel in New York City, during most of the year 1967. The system shared in the use of an IBM 7040 computer located at the IBM Research Center, forty miles away from the tunnel. The computer received via a telephone line signals from pairs of detectors located at four observation points along the tunnel. From these signals were determined the number of vehicles in the three sections of the tunnel between the four observation points, as well as the speed and throughput over these four points. The control system reduced the input of traffic into the tunnel when needed in order to prevent congestion, which has been known to reduce appreciably the throughput of the tunnel. It has been shown that knowledge of the exact number of vehicles in the three sections of the tunnel permits much more timely action than has been possible in the past, resulting in longer periods of sustained high flow at comfortable speeds. A discussion is given of the algorithms used for control, and an analysis of the experimental data is presented showing the improvement of controlled versus uncontrolled traffic. [ABSTRACT FROM AUTHOR]