Driving Path Indication Reduces Motion Sickness and Influences Head Motion of Passengers in Autonomous Personal Mobility Vehicle

Abstract

Autonomous personal mobility vehicles (APMVs) are novel smart mobility devices designed to provide automated individual transportation in indoor or mixed-traffic environments. However, in such environments, frequent pedestrian avoidance maneuvers may cause rapid steering adjustments and passive postural responses from passengers, thereby increasing the risk of motion sickness. This study investigated whether indicating the future driving path could mitigate motion sickness in APMV passengers. A mixed-design experiment was conducted with 40 participants under two self-reported genders as a between-subject factor (male and female), two driving paths as a between-subject factor (irregular and regular) and three driving conditions as a within-subject factor (manual driving (MD), automated driving without path indication (AD w/o path), and automated driving with path indication (AD w/ path)). Motion sickness was evaluated using the Motion Illness Symptom Classification (MISC), and head motion was assessed by calculating the delay time of participants' head yaw rate relative to APMV's yaw rate in the turning direction. The results showed that driving condition was the only factor that significantly affected both motion sickness and head-motion delay. Compared with the AD w/o path condition, both the MD and AD w/ path conditions were associated with lower motion sickness severity, longer motion sickness onset latency, and earlier head motion relative to vehicle motion. Notably, the AD w/ path condition achieved motion sickness levels comparable to those in the MD condition. Furthermore, repeated-measures correlation analysis showed significant associations between head-motion delay and all MISC metrics but the underlying physiological mechanism remains to be elucidated. These findings suggest that presenting information about future driving path can mitigate motion sickness in APMV passengers.