Experimental investigation of day-to-day route choice behaviour

The paper reports laboratory experiments on a day-to-day route choice game with two routes. Subjects had to choose between a main road M and a side road S. The capacity was greater for the main road. 18 subjects participated in each session. In equilibrium the number of subjects is 12 on M and 6 on S. Two treatments with 6 sessions each were run at the computerized Laboratory of Experimental Economics at Bonn University using RatImage [I]. Feedback was given in treatment I only about own travel time and in treatment 11 on travel time for M and S. Money payoffs increase with decreasing time. The main results are as follows: Though mean numbers on M and S are very near to the equilibrium, fluctuations persist until the end of the sessions in both treatments. The Fluctuations are smaller under treatment II. The effect is small but significant. The total number of changes is significantly greater in treatment I. Two response modes can be observed: A direct response mode reacts with more changes for bad payoffs whereas a contrary response mode shows opposite reactions. Subjects' road changes and payoffs are negatively correlated in all sessions.