Simulating Activity Chains: German Approach

Abstract

During the last decade a number of German researchers have developed a distinct form of urban‐transport modeling: the Monte‐Carlo simulation of urban travel based on the activity programs of the population. This approach was an attempt to answer to the perceived lack of behavioral realism in the four‐step transportation planning methodology. The daily activity program of the individual becomes the frame of reference for the decision submodels. The activity chains of the population are an input to the model. The approach follows the sequence of activities through the day. The approach restrains the decision submodels, especially destination choice and mode choice, to incorporate only those choice alternatives, which are at any point available to the decision maker. The paper describes the general approach and its background in a first section. The next section provides a more detailed description of some implementations of the model. A discussion of the problems and perspectives concludes the paper. The appendix describes in detail an iteration of an example algorithm.