California Partners for Advanced Transportation Technology

It is important that our travel be organized in an efficient way. One way to achieve this is to provide travelers with a trip planner that produces efficient travel itineraries for them. It is desired that a trip planner possess the following features in order to be useful: be able to handle multiple destinations, multiple constraints, and multiple modes; and be able to adjust travelers' preferences under different circumstances. These features cannot be found in existing trip planners. The goal is then to develop an "Itinerary Planner" that possesses all of these features. The Itinerary Planner attempts to identify the most desirable itinerary from among all feasible alternatives. The desirability of an itinerary is measured by an objective function, which is defined a weighted sum of seven criteria (i.e., attributes of the itinerary), The weights represent travelers' preferences to the attributes (e.g., total travel time and monetary cost). The Itinerary Planner first uses initial values of the preference weights established in a previous study in the Bay Area. After a series of operations, the Planner selects the two "best" itineraries which have the best and the second best objective function values. Then, the Planner presents the selected itineraries to the traveler. If the traveler is not satisfied with either itinerary, the Planner asks the traveler to indicate the itinerary that they prefer to the other. Based on the selection made by the user, the Planner updates the preference weights and re-selects another two itineraries. This process is repeated until the traveler is satisfied with one of the selected itineraries. A prototype is developed for downtown San Francisco. It is demonstrated that the Planner is capable of effectively generating alternative itineraries for a tour that involves multiple trips and multiple modes, with complex constraints, and that the Planner prototype serves as a practical tool for travelers in itinerary planning.