Motion Sickness in Automated Vehicles: Principal Research Questions and the Need for Common Protocols

Motion sickness in automated vehicles (AVs) represents a key Human Factors concern that will negatively impact the passenger experience and, ultimately, public acceptance. Minimizing or avoiding motion sickness altogether, therefore, becomes a strategic design goal. In this article we propose principal research questions that need to be addressed as part of a concerted effort to understand the causative factors of motion sickness and the need to develop and apply common protocols to accelerate knowledge and subsequent innovation in this field. With the ultimate goal to provide guidelines to inform the design of future vehicles, the International Organization for Standardization standard (ISO) 2631-1 (1997) is taken as the starting point. The current standard provides estimates of the likelihood of motion sickness as a function of vertical motion input only. However, in the context of AVs, and in particular in the light of anticipated non-driving-related activities in such vehicles, the current standard is of limited use: The model has not been validated for horizontal and rotational motions or any potential multi-axes interactions; The standard was derived on the basis of the percentage of passengers reaching the point of emesis while less severe levels of motion sickness are of greater interest and may show a different relationship between the frequency and acceleration; Modulating factors that are able to regulate, adjust, or adapt sickness levels are not included, in particular vision and the associated concept of anticipation, passenger orientation, and reclination angles. Finally, the accumulation of motion sickness knowledge in this field is severely hampered by the absence of consistent study protocols. We here propose the identification and development of appropriate vibration measurements and motion sickness assessment and evaluation methods.