When Stick-slip Hinders Human Positioning Performance

Abstract A haptic gas pedal was developed, which continuously displays inter-vehicle separation information to drivers during car following. The haptic information is generated by combining time-headway and time-to-contact to the lead vehicle. It is expected that haptic gas pedal feedback will allow drivers to better divide their attention between the car-following task and a secondary task demanding visual attention, than when driving without haptic gas pedal feedback. An experiment was conducted to investigate this hypothesis. Drivers were given a visual in-vehicle task: selecting tracks on a CD-player. In general, the haptic feedback system did not seem to significantly affect driving behavior, but yielded lower task-completion times in the more critical following situations compared to the condition without support. During execution, the secondary task greatly increased following headways, with and without haptic support. This is most likely the result of the driving strategy drivers apply when diverting their attention away from the driving scene: increasing the following gap.