Abstract:

Traditional metering signalization is designed for individual entry at roundabout with unbalanced vehicular demands, which could fail to avoid circulatory roadway from locking up. A new control strategy of full metering signalization at roundabout is proposed which can be used for multilane roundabout. Traffic detectors are placed on each approach and the circulatory roadway to detect time headways and occupancy times. Metering signals are installed on each approach and are used on a part-time basis. Metering signal operations can be managed in three modes. Four function modules driven by traffic events are designed to avoid circulatory roadway from locking up. These modules satisfy different levels of vehicular demands by dynamically changing the mode of metering signal operation and the durations of different color signals. VISSIM simulation results show that good performance of proposed full metering signalization is obtained in low and medium load demand scenarios. The poor performance in heavy load demand scenarios indicates the necessity to implement full signalization on every approach and on the circulatory roadway.

Key words: engineering of communication and transportation system, roundabout, yield rule control, traffic signal control, microscopic traffic simulation