This study analyzed cases of motion sickness induced in multiple experiments utilizing a vehicle simulator equipped with a motion platform (KMU-DS) and a simulation program, SCANeR Studio. This is to identify the major factors and mitigation strategies of motion sickness and contribute to the development of technologies preventing motion sickness. Three experiments conducted in a vehicle simulator environment over four years from 2018 to 2021 were analyzed for cases of motion sickness. In the first experiment, 31 participants out of a total of 186 dropped out due to motion sickness. In the second experiment, 7 out of 110 participants experienced motion sickness. The third experiment included a total of 95 participants, and none of them experienced motion sickness. The occurrence of motion sickness varied depending on factors such as manual/autonomous driving, gender, and age group. The results of motion sickness case analysis derived from this study are expected to be utilized for reducing motion sickness in participants during future simulator-based experiments. Furthermore, these findings can be applied to research and development of motion sickness mitigation technologies. For future research, simulator driving experiments incorporating quantitative indicators such as electrocardiography and qualitative indicators such as interviews will be conducted.