Conventional Diamond, Diverging Diamond, and Single Point Diamond Interchanges: A Comparative Operational Performance Evaluation in the Era of Connected Vehicles

This study evaluates the mobility impact of implementing Connected Vehicle (CV) technology at the Conventional Diamond Interchange (CDI), Diverging Diamond Interchange (DDI), and Single Point Diamond Interchange (SPDI). The evaluation is based on a microsimulation environment created in VISSIM combined with ASC/3 Software-in-the-Loop signal controllers and Python-programmed Vehicle to Infrastructure (V2I) communication algorithms. The effect of varying CV-Market Penetration Rates (CV-MPRs) on traffic operations is taken into consideration. The study shows that the interchange design has a higher impact on traffic operations than does the CV-MPR. Particularly, a 100% CV-MPR has led to 6.4% reductions in delays compared to the 0% CV-MPR, without considering the effect of interchange design. Contrarily, the CDI would increase delays as high as 24.0% as opposed to the SPDI, without considering the effect of CVs. Similarly, the DDI would reduce delays by up to 60.6% compared to the SPDI, without considering the effect of CVs.