An Introduction to Agent-Based User Equilibria

In daily work related to the development of the open source micro-simulation program SUMO [1] it has been observed, that users of SUMO very often do have a very basic understanding only of the idea of the user equilibrium (UE). Since most of the users of SUMO are not from the field of traffic engineering, this text will serve as an introduction into the computation of user equilibria in ITS applications. In addition, by way of two examples, it points out to open questions and also differences between the static world of traffic planning where the UE came from and the dynamic world of ITS. It shows the difference between logit-based and probit-based route choice, from the constructive view-point of an agent-based simulation. Finally, it is demonstrated that the UE and an urban traffic management center sometimes do not play well together.