Implementing a household joint activity-travel multi- agent simulation tool: first results

In recent years, there has been a growing interest in the social dimension of travel, and how travel decisions are influenced not only by the global state of the transportation system, but also by joint decisions and interactions with social contacts. Such joint decisions are particularly important for a variety of behaviors: leisure activities are often performed with social contacts, and their location and timing is thus the result of a joint process; household “maintenance” tasks, such as grocery shopping or driving the children to school, are allocated to one single member; and of course joint (car) travel is the result of complex joint decisions. For this reason, the need to include household and friendship relationships into mobility simulation frameworks is becoming more and more obvious. This paper presents a game theoretic framework for the study of joint decision making, as well as an algorithm to search for approximate solutions of the resulting game. An implementation of this algorithm for the household case, using the MATSim software framework, is proposed and tested. The implementation of this algorithm is tested for the Zürich area, Switzerland, focusing on the possibility to perform joint trips. Those results allow to identify strengths and weaknesses of the approach, and directions for future work.