Policy Effects on Decisions under Uncertain Conditions

The aim of this study is to assess the effects of incentives, in the form of toll reductions, introduced to entice commuters to use a toll expressway. Two market segments were targeted: everyday users, for whom the intended effect is to reduce peak-hour congestion by spreading entrances to expressways to off-peak hours, and low-frequency users, for whom the intended effect is to increase their expressway use over surface streets or public transit. To evaluate the effectiveness of toll reductions, an experiment was conducted on an expressway in Osaka, Japan, in which participants received a toll reduction at each expressway use. The experiment lasted for 6 weeks with toll discounts offered during the middle 4 weeks according to certain schedules. Data on the participants’ first trips of the day were collected over the 6-week period. Mixed logit models were developed to describe everyday users’ departure time choice and low-frequency users’ route choice, respectively, in accounting for preference heterogeneity across travelers. Simulation analyses were carried out with various policy options. The results underscore the significance of developing policy measures based on users’ time constraints and work-hour arrangements.