Dynamic User-Optimal Models with Variable Demand

In contrast to the DUO models with fixed demand, the DUO models with variable demand consider both elastic traffic demand and route choice within a mathematical program framework. The essence of this framework is the existence of feedback on network conditions, where the amount of O-D demand is determined by the corresponding minimal route travel times, which are in turn affected by the O-D demand through the traffic assignment procedure. Since the interactions between the variable demand and route choice decisions are treated within a unified framework, the internal inconsistencies that are apt to characterize conventional transportation planning procedures can be avoided. In consideration of the departure time choices, two types of models can be further identified, i.e., the DUO variable demand/route choice model, and the DUO variable demand/departure time/route choice model.