Highly Automated Ridesharing: Implications of Novel Seating Configurations and Seatbelt Use

Upcoming novel vehicle designs, such as vehicles equipped with Level 4 (L4) driving automation features, are intended to be used as rideshare automated vehicles (RAVs). In vehicles without L4 automation features, drivers typically receive all regulated telltales, indicators, and alerts intended to encourage seatbelt use. In a vehicle with L4 features, a driver is not present, meaning these alerts need to be presented directly to the occupants. Understanding occupant behavior in a novel vehicle design can inform effective methods for encouraging seatbelt use. Thirty participants rode in an RAV on a closed test track. Participants rode in groups of three on a 5-minute route at speeds up to 15 mph. There were two benches with three seats per bench: a forward-facing row and rear-facing row. Human-machine interfaces were placed overhead for each seating position; these included a novel seatbelt reminder alert (SBR) that would chime if the passenger was unbuckled when the vehicle started to move. If participants remained unbuckled, the SBR would last 10 seconds before doubling in tempo until the participant in that seating position was buckled. A post ride survey was administered to capture participant opinions of their experience. Where appropriate, results from a previous proprietary study of 60 single riders were compared to the current study. Group riders were significantly more likely to buckle before vehicle movement than single riders. Group riders were more likely to sit in the rear-facing row of seats than the single riders. Across all participants, females were more likely to buckle before vehicle movement than males. For those participants who received the SBR alert (i.e., those who were not buckled before vehicle movement), the majority began buckling within the first ~7-seconds of SBR presentation. Results suggest riding context can impact seatbelt use. Although a majority of participants preferred to face forward, group dynamics forced some participants to sit backwards in all rides. Further research is needed to understand the impact of riding environment, other rider populations, and SBRs on buckling behavior in RAVs.