Motion sickness is being highlighted as one of the most significant ride comfort issues for autonomous vehicles. Studies have attributed the feeling of motion sickness to the lateral motion of the vehicle. Additional studies have addressed that there is a meaningful correlation between the lateral motion of a passenger’s head with their feeling of motion sickness. Using bond graphs, a model of a vehicle with a sitting passenger on board is constructed which allows for computation of the vehicle’s lateral and roll motion as well as the lateral and roll motion of the passenger’s head. Furthermore, if the passenger’s head motion is available, the Motion Sickness Incidence (MSI) can be calculated using available literature. The objective of this research is to estimate motion sickness from the head roll motion for future use in developing a suspension control that will mitigate motion sickness.