The fastest itinerary in time-dependent decentralized travel information systems

A travel information system (TIS) provides customers with information about transportation, transfers, and routings. A decentralized TIS is composed of autonomous subsystems and a central computer, where local subsystems have full control of their data and there is not a complete database in the central computer about the entire TIS. The transportation vehicles are scheduled. A travel itinerary from one spot to another contains the travel path and the schedule of transportations. The approach presented in this paper is for the central computer to identify the fastest itinerary across autonomous subsystems, based on the incomplete local information provided by the independent subsystems.