Transition to Automated: The Interaction of Activating the In-vehicle Automated Driving System

Automated driving system (ADS) becomes more popularized in recent years, and the level 2 and level 3 ADS have already been equipped on several production car models in the market. The activating interaction of the ADS is very important since it is the very first step for users to manipulate and understand the system. However, most existing studies are focusing on the process of transition to manual—drivers taking over of the vehicles. We collected 21 different activating interactions that have already been equipped or proposed in production or concept cars, and explored their usability in a simulated driving environment with 30 recruited participants via a subjective evaluation. An experimenter measurement of the steering wheel turning angle was also included in order to compare the driving safety level between different activating interactions. With the ANOVAs of the usability score and steering wheel turning angle done, the result shows that six interactions “press the button on the right part of the steering wheel”, “press the button on the left part of the steering wheel”, “press the button on the center console”, “pull the paddle behind the steering wheel on the right once”, “pull the left and right paddles behind the steering wheel together once” and “keep pulling the left and right paddles behind the steering wheel for 1 s” are recommended for the ADS in terms of offering great usability and ensuring basic driving safety.