Internal causes of return trip effect based on eye movement and EEG indices

When traveling by car, the driver normally feels that the return trip is shorter than the outbound trip. The reason for this feeling, called return trip effect, is not clear. To explore the internal causes of this return trip effect, an indoor driving simulation experiment and a real car driving experiment were performed in this study. Questionnaires were used to obtain the estimated time of the outbound and return trips of the drivers. An eye tracker and an electroencephalograph equipment were used to record driver's eye movement and EEG data in the real-car driving experiment. The physiological indices and questionnaire results showed that the difference in the driver's cognitive loads of the outbound and return trips was the internal cause of the return trip effect. Drivers who were unfamiliar with the road had a different cognitive load between the two trips, which resulted in the return trip effect. However, drivers who were familiar with the road did not experience a return trip effect due to the close cognitive loads of the two trips.