A necessity in driving simulation testing is to understand and attenuate simulator sickness in urban environments to reduce the number of undesired drop-outs. This final thesis explains a 6 degree-of-freedom simulator sickness prediction model based on observer theory including the visual system. The model incorporates state-of-the-art knowledge of human spatial orientation perception and qualitative theories that try to explain motion sickness. Predictions are made regarding the simulator sickness incidence and expected rotary and translational motions for different motion and sensory paradigms. A between-subjects experiment was conducted to verify the model. Furthermore, the effect of adding scaled, but veridical, yaw motion to a simulator on the sickness incidence and severity while driving in urban environments was investigated. Participants were required to indicate a misery scale score every minute and to fill in the simulator sickness questionnaire prior to and after the experiment. Additionally, the perceived motion incongruence was measured together with head movements. Three cases were considered; a no-motion case, a case with a scaled yaw movement and a case with a scaled yaw movement together with pitch and roll motions. A significant relationship has been found between the simulator sickness prediction model outputs and the experimental outputs. Therefore, the model with the implemented visual system could be used to better understand
and predict simulator sickness. A significant relationship has also been found between the measured perceived motion incongruence and the simulator sickness incidence. This perceived motion incongruence can be used to quantify a part of the qualitative sensory rearrangement theory. Furthermore, humans that indicated lower sickness scores, moved their head significantly more along with the direction of the curve. Head movement strategies can be taught to participants of simulator studies to attenuate simulator sickness symptoms. Finally, significantly less participants dropped out in the cases that included simulator motion when driving in urban environments. The findings in this final thesis could assist in attenuating the number of drop-outs during driving simulation testing in urban scenarios.