Traffic signal phase truncation in the event of traffic flow restriction

by 1978- Beaird, Scott Glenn

This thesis presents a proposed improvement to traffic signal controller logic. The concept consists of truncating a phase on which there is demand but zero or minimal flow due to a restriction of traffic. The logic presented in this thesis recognizes such a flow restriction and, consequently, terminates the phase in favor of a conflicting call for service. The theory of the concept is addressed and methods of implementation are explored. An experimental analysis was conducted in order to qualify the benefit of the phase truncation concept. This analysis was conducted using the VISSIM simulation software in conjunction with a hardware-in-the-loop configuration. This permitted the simulation to be run using an actual traffic signal controller. The simulation analysis was conducted using an eight-phase actuated intersection. Based upon the results of this analysis, it was concluded that the phase truncation concept could result in reduced vehicle delay. v