The article describes an operational traffic flow control in a vehicular tunnel, thereby using photoconductive cells as vehicle detectors and a fixed logic hardware controller to activate the relevant traffic signals at the tunnel entrance. The vehicle detectors use wall-mounted high-intensity light sources aimed at a cell which is located below a hole in the tunnel roadway. The cell is connected to the controller which in turn utilizes discrete solid-state components to determine the number of vehicles between two points in the tunnel lane. In addition, the controller also calculates the speed of each vehicle at both points. A comprehensive traffic flow control and stoppage-detection system using four small-scale digital computers is also discussed.
Samenvatting