Integrated Control of Internal Boundaries and Signal Timing at An Isolated Intersection for Lane-Free Traffic of CAVs.

Urban traffic signal timing separates incompatible traffic flows in time, but normally cannot intervene in the utilization of road resources when the bi-directional (e.g. east and west bound) traffic demands are much unbalanced, because such demands receive the same right of way. A novel traffic control measure called internal boundary control (IBC) was recently proposed to address a similar concern on freeways for lane-free traffic of fully connected automated vehicles (CAVs). This paper applies the idea of IBC to maximize the utilization of intersection resources for improved urban traffic efficiency. The paper focuses on the joint optimization of roads' internal boundaries and signal timing for an isolated intersection in the paradigm of lane-free traffic of CAVs. The optimization problem is formulated as a binary-mixed-integer-quadratic-programing problem. The results show that the joint optimization has a potential of significantly improving traffic situations at an intersection, typically those intractable via signal timing optimization alone.