A dynamic traffic assignment framework has been described in which travelers' pre-trip and en-route choices are modeled, including the influence of the pre-trip route choice on the later en-route decisions. Travelers' route choice sets are extended during the dynamic traffic flow simulation to include all reasonable routes from all intersections to all destinations. The en-route route flows are the computed by applying a relative multinominal logit model, in which the generalized route costs include a possible utility for following the route that is chosen pre-trip. The latter is represented by the route overlap factor and a weighting parameter which may also be interpreted as a threshold to deviate from the pre-trip route choice. The proposed framework is widely applicable in dynamic traffic assignment applications, since it enables modeling the synthesis of pre-trip (or dictated) and en-route choices due to, for instance, route guidance, evacuation instructions and unexpected traffic or network conditions (e.g., incidents, accidents and road works), as well as providing a solution to possible gridlock, and is capable of dealing with failure of links.
The different versions of the original document can be found in: