Haptic in-seat feedback for lane departure warning.

A Lane Departure Warning (LDW) system for trucks was developed and evaluated in an iterative design process. As the auditory warning signals used by the majority of LDW systems are disliked by drivers, most effort was put in the design of haptic warning signals. The iterative design process resulted in two different haptic warning signals displayed through vibration motors in the seat: a "blinking" signal for Medium Criticality departures and a continuously vibrating signal for High Criticality departures. In addition, the iterative design process also resulted in small modifications in the auditory warning signals. The effectiveness and user acceptance of the haptic and auditory warning signals were evaluated in an experiment with a driving simulator with 20 participants and in a road test with a truck with 5 participants. It was found that the haptic warning signals were as effective as the auditory warning signals in dealing with lane departures, both in normal driving situations and in a driving + secondary task situation. In addition, the participants clearly preferred the haptic signals over the auditory warning signals.