Car drivers attend to different gaze targets when negotiating closed vs. open bends

Area of Science:

• Human-Computer Interaction
• Automotive Engineering
• Cognitive Psychology

Background:

• Steering control on winding roads requires managing speed and steering angle for optimal lane positioning.
• Proposed steering strategies include the tangent point method and gaze sampling, with prior studies yielding mixed results across different scenarios and road designs.

Purpose of the Study:

• To investigate the impact of bend openness (driver's sight distance) on the utilization of the tangent point strategy in car driving.
• To quantify the percentage of tangent point usage in relation to road curvature and sightline visibility.

Main Methods:

• Six drivers operated a test vehicle on real roads, navigating twelve distinct bends.
• Eye-movements of drivers were continuously recorded throughout the driving task.
• Analysis focused on correlating driving strategy (tangent point usage) with bend characteristics (openness, curvature).

Main Results:

• Drivers demonstrated a high general reliance on the tangent point strategy.
• Tangent point usage significantly increased with greater bend 'closedness' (reduced sight distance) and higher road curvature.
• In open bends, drivers shifted their gaze to distant straight road segments rather than employing gaze sampling.

Conclusions:

• The tangent point strategy is a dominant method for steering control in winding road conditions.
• Driver's visual strategy adapts to road geometry, favoring the tangent point in constrained visibility and high-curvature situations.
• Gaze sampling is not utilized by drivers in open bends, indicating a preference for distant visual cues.