Analysis Of Driver Visual Attention When Driving With Different Levels Of Haptic Steering Guidance

Highly automated driving tremendously reduces workload of drivers. However, the drivers may lose their visual attention to road ahead due to the out-of-the-loop problem. Haptic guidance has been developed to reduce drivers' workload while keeping the drivers in the control loop. The haptic guidance system continuously provides assistant torques on the steering wheel so that both the driver and the system contribute to the steering input. This paper focuses on analyzing drivers' visual attention to road ahead and response to critical events when driving with different levels of haptic guidance. A simulator experiment with five participants was conducted. There were five driving conditions: hands free, hands ready, strong guidance, weak guidance, and manual driving. Autopilot driving was realized by the highest level of haptic guidance in the conditions of hands free and hands ready. Results indicate that percent road center was significantly higher in the condition of weak guidance compared to hands ready. Root mean square of steering torque was significantly lower in the condition of weak guidance compared to manual driving. Moreover, the drivers' response to the critical event indicates that lane change maneuver was smooth in the conditions of weak guidance and strong guidance.