Assessing Alternative Approaches for Conveying Automated Vehicle “Intentions”

Research suggests the general public has inherent distrust in highly automated vehicles (HAV), typically stemming from a lack of vehicle system transparency while in motion (e.g., the user not being informed how the car will react in the upcoming scene) and not having an effective way to control the vehicle in the event of a system failure. To better understand user trust and perceptions of comfort and safety while riding in an HAV, this study evaluated
in-situ
human-machine interface (HMI) systems (visual, auditory, and mixed-modal) to relay vehicle “intentions” (e.g., the vehicle's response to roadway stimuli) to the user. A considerable link was found between HMI modality and users’ reported levels of comfort, safety, and trust during experimentation. In addition, several key behavioral traits are identified as factors that contributed to users’ baseline comfort levels with the HAV. Moving forward, it will be necessary for HAV systems to keep users in-the-loop in an effort to increase system transparency and overall understanding. Vehicle feedback should consistently and accurately represent the driving landscape and clearly communicate vehicle system state to users.