Drivers’ Route Choice Rules and Network Behavior: Do Drivers Become Rational and Homogeneous Through Learning?

Most analyses of driver-network transportation systems rest on the presence of network equilibrium. Equilibrium analyses presuppose that the driver is rational and homogeneous and has perfect information. A more realistic view, however, is that individuals’ rationality is bounded because of their cognitive limitations. A driver is assumed to adopt simple rules when he chooses a route. A model system in which the driver’s learning is simulated with multiple rules is applied to investigate the validity of the hypotheses underlying network equilibrium. The results of simulation analyses can be summarized as follows. Drivers do not become homogeneous and rational, as equilibrium analyses presuppose; rather, there are fewer rational drivers even after a long process of learning, and heterogeneous drivers make up the system. Drivers’ attitudes toward and perceptions of each route do not become homogeneous either but become bipolar. The results point to the need for a critical appraisal of the foundation of the equilibrium analysis of network flow.