A cell-based traffic control formulation: Strategies and benefits of dynamic timing plans

This study developed a dynamic traffic-control formulation that considers the entire Fundamental Diagram. This incorporation of the Fundamental Diagram is especially important for modeling oversaturated traffic. For this purpose, traffic is modeled after the cell-transmission model (CTM), which is a convergent numerical approximation to the hydro-dynamic model. We transformed CTM to a set of mixed-integer constraints and subsequently cast the dynamic signal-control problem to a mixed-integer linear program. As a dynamic platform, the formulation is flexible in dealing with dynamic timing plans and traffic patterns. It can derive dynamic as well as fixed timing plans and address preexisting traffic conditions and time-dependent demand patterns. This study produced results to show the benefit of dynamic timing plans and demonstrated that some of the existing practice on signal coordination could be further improved.