In this project, researchers developed and field-tested an intelligent traffic control system for identifying and progressing platoons at isolated traffic signals on signalized arterials. The main focus of research are signals located downstream of other traffic signals. However, the system can also be installed at sites where an upstream signal does not exist but where platoons naturally form. This system uses advance detection to obtain real-time information about the presence and speeds of individual vehicles. Then, it uses an algorithm developed by researchers to identify if a platoon--of a user-specified size and density--is approaching the signal and estimated platoon arrival time at the stopbar. When the system identifies a platoon, it issues a low-priority preemption signal to progress the detected platoon. The duration of the initial preemption signal is based on estimated arrival and departure times for the smallest acceptable platoon. Then, the system switches to an extension mode and provides progression to any additional vehicles determined to be in the platoon. It accomplishes this by increasing preemption time until such time as no more vehicles are determined to be in the platoon or the max-timer expires. The system also ensures that the last progressed vehicle does not get trapped in its dilemma zone. This document describes research and development work conducted in this project. (Author/publisher)
Abstract