  We introduce a new conservation-based approach for traffic coordination
modeling and control in a network of interconnected roads (NOIR) with switching
movement phase rotations at every NOIR junction. For modeling of traffic
evolution, we first assume that the movement phase rotation is cyclic at every
NOIR junction, but the duration of each movement phase can be arbitrarily
commanded by traffic signals. Then, we propose a novel concurrent switching
dynamics (CSD) with deterministic transitions among a finite number of states,
representing the NOIR movement phases. We define the CSD control as a cyclic
receding horizon optimization problem with periodic quadratic cost and
constraints. More specifically, the cost is defined so that the traffic density
is minimized and the boundary inflow is uniformly distributed over the boundary
inlet roads, whereas the cost parameters are periodically changed with time.
The constraints are linear and imposed by a trapezoidal fundamental diagram at
every NOIR road so that traffic feasibility is assured and traffic
over-saturation is avoided. The success of the proposed traffic boundary
control is demonstrated by simulation of traffic congestion control in Downtown
Phoenix.
