Author: Daizong Liu , Ruey Long Cheu
TRANSYT is one of the most popular offline computer programs for optimizing signal timing plans for a network of intersections with a fixed volume. SCATS is one of most widely used real-time traffic control systems. This research compares the traffic operations along an arterial corridor with four intersections when the signal timing plans were calculated or controlled dynamically by TRANSYT and a localized version of SCATS logic (known in Singapore as GLIDE) respectively, by means of microscopic traffic simulations using PARAMICS. To use Version 11 of TRANSYT for dynamic update of signal timing plans during PARAMICS simulations, an interface program has been developed to exchange traffic data and signal timing plans between PARAMICS and TRANSYT at regular intervals. The logic of SCATS timing plan selection for a sub-system of intersections has also been coded in a plug-in program for PARAMICS. The results of our simulation evaluation has shown that, using TRANSYT with signal timing plans updated at every 45 minutes, the vehicles in the network experienced relatively smaller average delay compared to under SCATS-based control.