Effects of Cognitive Distraction and Driving Environment Complexity on Adaptive Cruise Control Use and Its Impact on Driving Performance: A Simulator Study

As driving automation features are increasingly integrated into vehicles to enhance safety and comfort, new risks and challenges emerge in the transition towards full automation. Here, we adopt a human-centered approach to explore whether and how drivers’ cognitive state and driving environment complexity influence reliance on driving automation features. Besides, we examine whether such reliance affects driving performance. Participants operated a vehicle equipped with adaptive cruise control (ACC) in a simulator across six predefined driving scenarios. In each scenario, they were either engaged in a cognitively demanding task (i.e., responding to mental calculations) or not (cognitive distraction, 2 levels), while experiencing different traffic conditions (driving environment complexity, 3 levels). Throughout the experiment, participants had to respect speed limits and were free to activate or deactivate ACC. In complex driving environments, we found that more frequent ACC activations and deactivations occurred and that the overall ACC engagement time was lower compared to less complex driving environments. We observed no significant effect of cognitive load on ACC use. Furthermore, while ACC use had no effect on the number of lane changes, it did impact the speed limits compliance.