Previous analyses of gaze behaviour in bends have shown that drivers look frequently in the direction of the tangent point (TP). Several models have sought to explain how and why this part of the road provides the driver with an input signal which guides steering (Boer 1996, Land 1998, Salvucci & Gray 2004). To investigate further, an experiment was performed where subjects negotiated a series of bends in a simulator setting while looking at a visual target. This target was positioned on the TP or at the same distance but with a lateral offset, either on the inside or outside of the driving lane. In a control condition, drivers were allowed to perform an unconstrained sampling of the visual scene. The data revealed that the lateral positioning of the car remained unchanged when drivers looked at the driving lane. In contrast, when drivers looked at the TP or further inside the bend, this resulted in contralateral deviation of the trajectory. It was also seen that the trajectory stability increased when the driver was given a target point, irrespective of the position of that point. These results confirm the close relationship that exists between gaze positioning and steering behaviour. They support the hypothesis that looking at the future path of travel is the most effective strategy for driving in bends. They also suggest that explicitly providing a relevant visual cue to the driver may assist him in the control of his car. (Author/publisher)
Samenvatting