The Effects of Connectivity on Intersection Operations with “White Phase”

This paper analyzes the impact of infrastructure to vehicle communication on mobility and safety performance measures at isolated signalized intersections with white phase. During white phases, the intersection controller optimizes the trajectory of connected automated vehicles (CAV) to lead a group of connected human-driven vehicles (CHV) and navigate them through the intersection. White phase can be assigned to conflicting movements simultaneously to mimic the signal-free intersection logic within a mixed autonomy environment where the safety of the shared fleet is ensured by optimally controlling the movements of CAVs. Red and green signal indications can be used to ensure safety when there are not enough CAVs in the vicinity of the intersection. The problem is formulated as an optimization model and solved using a receding horizon framework. One demand level and five CAV market shares are used to assess the effects of connectivity on traffic operations and safety. Case studies are tested with three connectivity levels: 1) no-connectivity, 2) connected without white phase (no-white-phase), and 3) connected with white phase (optimized-white-phase). The results indicate that average delay decreases as the CAV market share and level of connectivity increase.