Take-over requests in highly automated driving: A crowdsourcing survey on auditory, vibrotactile, and visual displays

Abstract

An important research question in the domain of highly automated driving is how to aid drivers in transitions between manual and automated control. Until highly automated cars are available, knowledge on this topic has to be obtained via simulators and self-report questionnaires. Using crowdsourcing, we surveyed 1692 people on auditory, visual, and vibrotactile take-over requests (TORs) in highly automated driving. The survey presented recordings of auditory messages and illustrations of visual and vibrational messages in traffic scenarios of various urgency levels. Multimodal TORs were the most preferred option in high-urgency scenarios. Auditory TORs were the most preferred option in lowurgency scenarios and as a confirmation message that the system is ready to switch from manual to automated mode. For low-urgency scenarios, visual-only TORs were more preferred than vibration-only TORs. Beeps with shorter interpulse intervals were perceived as more urgent, with Stevens' power law yielding an accurate fit to the data. Spoken messages were more accepted than abstract sounds, and the female voice was more preferred than the male voice. Preferences and perceived urgency ratings were similar in middle-and high-income countries. In summary, this international survey showed that people's preferences for TOR types in highly automated driving depend on the urgency of the situation.

Catch My Drift: Elevating Situation Awareness for Highly Automated Driving with an Explanatory Windshield Display User Interface

“…Since auditory and vibrotactile signals are more restricted concerning the communication of more complex information, we regarded visual as the primary modality for this work. As mentioned in the background, however, existing work especially from the domain of semi-automated driving hints at the importance of multi-modal feedback [35,36]. We believe that auditory and vibrotactile output may play a role in different forms when combined with an explanatory UI.…”

“…In a full-automation scenario, however, we need to reconsider which tests are really fitting, depending e.g., on the importance of mental workload and if non-driving tasks are part of an experiment. Large-sample studies [35,36] showed users' preferences for multi-modal TOR feedback. The most popular options for announcements included, in this order: female voice take-over message, visual warning message, warning light, two warning beeps and vibrations in the seat.…”

Automated Vehicle Handover Interface Design: Focus Groups with Learner, Intermediate and Advanced Drivers

“…Perhaps the most discussed topic across all groups was the need for customization, a topic previously explored by Bazilinskyy and his colleagues [64,65]. The concept of customization in this study centered primarily on the modality in which information is displayed to the driver (e.g., "Well, I know I've got two kids in the back, and they're going to be singing or something,… So vocal things aren't going to cut it today"; intermediate group, participant 4), but also on how much time in advance drivers were alerted for the purpose of concluding secondary tasks or time OOTL (e.g., "I know I'm waiting on an important email, no matter what time you wake me up, I'm going to have to somehow finish it, and slam down my laptop, so I want 2 miles notice, not one"; advanced group, participant 3; "you're going to Romsey (from Southampton) you set the timer to 1 min, and if you go to Newcastle you set it to 3 to 5 min"; learner group, participant 5).…”

Secondary task and situation awareness, a mobile application for semi-autonomous vehicle

“…Analyses des Take-Over Request L'état de l'art sur les Take-over requests (TOR) (appelé demande de reprise de contrôle) a permis de démontrer leur usage en tant qu'objet primaire de recherche dans le cadre des IHV (Interaction Homme-Vehicule) [7], [17], [23], mais aussi en tant qu'évaluateur de la SA [21]. L'acceptation des TOR par les utilisateurs a aussi été étudiée [5], avec plusieurs conclusions à considérer, notamment une préférence des utilisateurs pour les signaux multimodaux en cas de situation critique, ce qui est le cas dans le cadre de cette expérience. Concernant la modalité auditive, les messages vocaux sont également préférés aux sons abstraits [5].…”