Breaking Car Use Habits: The Effectiveness of a Free One-Month Travelcard

Document Type

Journal Article

Publication Date


Subject Area

infrastructure - vehicle, planning - marketing/promotion, ridership - mode choice, ridership - drivers, ridership - attitudes, mode - mass transit, mode - car


Transit, Public transit, Motor vehicle operators, Mode choice, Modal shift, Modal choice, Mental attitudes, Mass transit, Marketing, Local transit, Kobenhavn (Denmark), Habits, Field studies, Drivers, Copenhagen (Denmark), Choice of transportation, Attitudes


This paper describes a field experiment designed to test a tool aimed to entice drivers to skip the habitual choice of the car and instead consider using (or at least trying) public transportation. About 1,000 automobile drivers in the greater Copenhagen region participated in the experiment either as experimental subjects receiving a free one-month travelcard, or as control subjects. As predicted, the results indicated that the intervention had a significant impact on drivers’ use of public transport. It also neutralized the impact of car driving habits on mode choice. However, in the longer run (4 months after the experiment) experimental subjects did not use public transport more than control subjects. These findings indicate that although many car drivers choose travel mode habitually, their final choice is consistent with their informed preferences, given the current price-quality relationships of the various options. Results from a questionnaire suggest that the trial experience did seemingly improve attitudes about commuting by public transportation, but that the trial experience was not sufficiently convincing to make average attitudes positive. A promotional offer such as the one tested here may be an effective way to reach potential customers who would use public transportation if they were fully informed, but only as a supplement to the basic marketing principle of offering a good service at a fair price.