SCOOT and SCATS: Closer Look into Their Operations

Abstract

SCOOT and SCATS are the most widely deployed Adaptive Traffic Control Systems worldwide. These proprietary systems have long been surrounded by their advocates and critics. This paper serves to illuminate the structural differences between these two methods. The authors present a detailed comparison of SCOOT and SCATS signal timings and their influence on traffic performance measures in microsimulation. SCOOT traffic control was provided by an academic site license and simulated in VISSIM. SCATS traffic control was deployed in Park City, Utah, which served as the test bed. Two segments from the 14-intersection Park City network were selected for analysis. We analyze and discuss SCOOT and SCATS implementations of cycle lengths, offsets, splits, and relevant performance measures from VISSIM. Findings show overall that SCOOT and SCATS deliver similar delays with different cycle lengths. SCATS seems to be somewhat better in implementing offsets and splits than SCOOT. Further research should address proper calibration and fine-tuning of these systems. Deficiencies in these processes may have a more profound effect on system performance than differences between SCOOT and SCATS algorithms.