Taking back the wheel: transition of control from automated cars and trucks to manual driving

Driving automation holds great promise for safer and more efficient road transportation, and is becoming a reality thanks to the rapid advancement of technology. However, before full driving automation arrives, the driver would have to take over control of the vehicle when the system fails or reaches its operational limits, which poses new road safety risks at different stages of development. When the system is less capable and reliable, the driver has to closely monitor the system and take over imminent control when necessary. This challenges humans’ inherent weak point of staying vigilant over a prolonged period of time. When the technology becomes more mature, the driver would be allowed to engage in a wide range of non-driving tasks, but occasional human interventions still cannot be avoided. How to ensure drivers in various mental and physical states to take over control safely become a major challenge at this stage. A large number of studies have tackled human factors issues related to control transitions, and suggested that no single take-over time budget applies to all drivers in all situations. While an adaptive approach is called for to support individual drivers in taking over control, a better
understanding of driver take-over process and the variability between and within drivers is still needed to achieve this goal.

This PhD thesis addresses the challenges stated above and contributes to designing safe and comfortable control transitions to manual. A particular focus was on control transitions in truck platooning scenarios, which have received only limited attention despite of the significance of platooning technology. The first objective is to explore factors influencing the take-over response time and its variability, and to gain a deeper insight in the actual take-over process. The second objective is to systematically study professional drivers’ take-over performance in truck platooning scenarios, in order to deliver input for the development of platooning systems and the corresponding infrastructures. The third objective is to design and evaluate potential approaches that prime drivers for a safe and smooth take-over, and to discuss the feasibility of an adaptive and personalized control transition approach.