Comparing Common Control Group treatment and signal coordination of intersections with separate controllers

Abstract

Common Control Group is a SIDRA INTERSECTION software term used for a group of signalised intersections controlled by a single signal controller. This is relevant to the modelling of signalised paired (closely-spaced) intersections and interchanges such as staggered T intersections, freeway interchanges, intersections with median area controlled by signals, fully-signalised roundabouts as well as alternative intersection and interchange types such as continuous flow intersection and diverging diamond interchange. The signal timing analysis for a Common Control Group is carried out using a single-phase sequence that incorporates all movements at the facility. This differs from the signal timing method for a network of separate intersections with signal coordination operating under a common cycle time. This presentation explains the reason for difference in network performances resulting from the two methods of signal control using a simple example including results from the SIDRA INTERSECTION software.