MODELING INTER CITY TRAVEL DEMAND WITH CONSTRAINT LOGIC

摘要

This paper suggests an alternative framework for inter-city passenger models. The new approach differs from traditional methods by making intensive use of Constraint Logic Programming (CLP) as a modeling language, integrating constraint logic reasoning with existing decision support systems technology. Conclusions entailed by the model can be used for a strict logical deduction of an adequate transport supply structure as well as to perform back-cast search. An activity-based travel demand model, which is entirely formulated with a network of constraint predicates, is being presented. The model's distinguishing features are (1) the introduction of numerous constraints narrowing down the individual's multidimensional choice sets as well as (2) the structuring of the decision process by time horizons instead of respective dimensions of aggregated travel demand. The approach was tested in a study on inter-city railway supply planning in Germany. A conventional planning system - comprising a quasi-direct demand model and the corresponding multi-modal supply model-served as a reference frame.