Game Theoretic Best-Response Dynamics for Evacuees' Exit Selection

We present a model for evacuees' exit selection in emergency evacuations. The model is based on the game theoretic concept of best-response dynamics, where each player updates his strategy periodically by reacting optimally to other players' strategies. A fixed point of the system of all players' best-response functions defines a Nash equilibrium (NE) of the game. In the model, the players are the evacuees and the strategies are the possible target exits. We present a mathematical formulation for the model and show that the game has a NE with pure strategies. We also analyze different iterative methods for finding the NE and derive an upper bound for the number of iterations needed to find the equilibrium. Numerical simulations are used to analyze the properties of the model.