Dynamic activity-travel assignment in multi-state supernetworks

The integration of activity‐based modeling and dynamic traffic assignment for travel demand analysis has recently attracted ever‐increasing attention. However, related studies have limitations either on the integration structure or the number of choice facets being captured. This paper proposes a formulation of dynamic activity‐travel assignment (DATA) in the framework of multi‐state supernetworks, in which any path through a personalized supernetwork represents a particular activity‐travel pattern (ATP) at a high level of spatial and temporal detail. DATA is formulated as a discrete‐time dynamic user equilibrium (DUE) problem, which is reformulated as an equivalent variational inequality (VI) problem. A generalized dynamic link disutility function is established with the accommodation of different characteristics of the links in the supernetworks. Flow constraints and non‐uniqueness of equilibria are also investigated. In the proposed formulation, the choices of departure time, route, mode, activity sequence, activity and parking location are all unified into one time‐dependent ATP choice. As a result, the interdependences among all these choice facets can be readily captured. A solution algorithm based on the route‐swapping mechanism is adopted to find the user equilibrium. A numerical example with simulated scenarios is provided to demonstrate the advantages of the proposed approach.