A LINK-BASED VARIATIONAL INEQUALITY MODEL FOR DYNAMIC DEPARTURE TIME ROUTE CHOICE/

The dynamic user-optimal (DUG) departure time and route choice problem is to determine travelers' best departure times and route choices at each instant of time. In a previous paper, we presented a route-based two-level optimal control model for the DUO departure time/route choic e problem. However, this model is not appropriate for large scale tran sportation networks because some degree of route enumeration is necess ary to solve the model. In this paper, we present a link-based variati onal in equality (VI) formulation for the DUO departure time/route cho ice problem so that route enumeration can be avoided in both the formu lation and the solution procedure. The model extends our previous VI m odel for the DUO route choice problem to the case where both departure lime and route over a general road network must be chosen simultaneou sly. By proving the necessity and sufficiency of this VI, we establish the equivalence of the VI formulation and the link-based DUO departur e time/route choice conditions.