“…Since second-order, PDE traffic flow models (i.e., systems that incorporate two PDE states, one for traffic density and one for traffic speed) constitute realistic descriptions of the traffic dynamics, capturing important phenomena, such as, for example, stop-and-go traffic, capacity drop, etc. [15], [28], [33], boundary control designs are recently developed for such systems [6], [26], [28], [49], [50], [53], [54] some of which are based on techniques originally developed for control of systems of hyperbolic PDEs, such as, for example, [12], [18], [25], [29], [31], [36], [46]. Even though simpler, first-order traffic flow models, in conservation law or Hamilton-Jacobi PDE formulation, are also important for modeling purposes.…”