Novel Continuous Green T Application at Partial Cloverleaf Interchanges: A Comprehensive Assessment

Abstract: This study investigates the benefits of implementing the continuous green-T (CGT) intersection at partial cloverleaf (parclo) A interchange ramp terminals in terms of vehicular arterial traffic operations. The goal is to provide practitioners and decision makers with a geometric treatment that could be implemented at existing parclo A interchanges to improve their performance. The resulting design from this implementation is called the CGT-parclo A interchange. To assess its operational benefits, the performance of CGT-parclo A was compared to the single point diamond interchange (SPDI), conventional diamond interchange (CDI), diverging diamond interchange (DDI), parclo A and the parclo progressA in simulation case studies. The simulation models were created in VISSIM using field collected data for three interchanges and six different traffic volume combinations in Utah. The results indicated improved operational performance at parclo A interchanges as a result of implementing CGT intersections at their ramp terminals. In addition, the CGT-parclo A design resulted in a better performance when compared to the SPDI, CDI, DDI, parclo A and the parclo progressA under the studied conditions. Mainly, the CGT-parclo A has shown better performance in accommodating heavy through traffic demands without compromising off- and on-ramp traffic performance. This is attributed to the nature of the CGT-parclo A design which allows for free-flow operations for each through movement at one of the ramp terminals. The CGT-parclo A also recorded lower vehicular delays, reduced number of stops and shorter queue lengths for existing and future conditions compared to the other designs.