Combined Phase Design Model for Multileg Roundabout Intersections

Abstract

Multileg roundabout intersections are widely used in urban areas worldwide. However, its traffic organization and signal control are very complicated in the case of large traffic flow, and the signal optimization methods for conventional intersections are not suitable for applying directly to roundabouts due to the complexity of the operating process. Therefore, many scholars have focused on dedicated signal timing schemes for roundabouts, especially through tuning key parameters such as signal cycle and green light time. However, research and applications regarding variable phases at roundabouts are quite rare. To address this gap, this paper analyzes the traffic flow characteristics and capacity of multileg roundabouts and proposed a combined phase design model to achieve the maximum utilization of road capacity at roundabouts, which can generate the optimal phase scheme based on real-time traffic data. The feasibility of the combined phase design model is verified by a case study in Jinhua, China. The results indicate that the proposed combined phase design model can improve the applicability of actuated signal control and the reasonableness of signal timing for multileg roundabouts and thus further improve the roundabout efficiency.

Modeling of Queue Detector Location at Signalized Roundabouts via VISSIM Micro-Simulation Software in Amman City, Jordan

“…The use of detector technology has been established, with early versions capable of detecting the presence of vehicles as they passed over the detectors at the junctions. Traffic signal systems have become more prevalent in recent times [30][31][32][33]. Adaptive strategies, which are a modified version of actuated control, use available data to predict the cycle length required for current traffic conditions.…”

“…Previous research has shown that fixed-time signal control or multi-period fixed-time control is only suitable for intersections with steady traffic, while actuated signal control is more appropriate for multi-leg roundabouts with unstable traffic [31]. However, the use of actuated signal control has not been successful in handling traffic flow in roundabouts, leading researchers to focus on studying roundabout capacity and adaptive signal control [18,26,32,36,37]. Moreover, the adaptive signal control system, specifically designed for roundabouts, was developed to improve their efficiency [28,38].…”