Route choice in pedestrian simulation: Design and evaluation of a model based on empirical observations

Several issues in transferring AI results in crowd modeling and simulation are due to the fact that control applications are aimed achieving optimal solutions, whereas simulations have to deal with the notions of plausibility and validity. The latter requires empirical evidences that, for some specific phenomena, are still scarce and hard to acquire. To face this issue, the present work presents an investigation on the route choice decisions of pedestrians, by producing empirical evidences with an experiment executed in a controlled setting. The experiment involves human participants facing a relatively simple choice among different paths (i.e. choose one of two available gateways leading to the same target area) in which, however, they face a trade-off situation between length of the trajectory to be covered and estimated travel time, considering the level of congestion in the different paths. The data achieved with the experiment are used to design and evaluate a general simulation model for pedestrian route choice. The proposed model firstly considers the fact that other pedestrians are generally perceived as repulsive and that choice of route is generally aimed at avoiding congestion (as for proxemics theory). On the other hand, we also introduce an additional mechanism due to the conjecture that the decision of a pedestrian to reconsider the adopted path is a locally perceivable event that is able to trigger a similar reconsideration by nearby pedestrians, that can imitate the former one. The model is experimented and evaluated in the experiment scenario, for calibration and validation, as well as in a larger scale environment, for exploring the implications of the modeling choices in a more complex situation.