Even though it is essential to the vehicle control process and vehicle evaluation, few studies take into account the human sensation and perception whilst driving. In this project, we will investigate the driver's perception of acceleration in driving simulators depends on human sensory factors such as optic flow (visual system), otolith stimulation (vestibular system), and vibration (somatosensory system). More importantly, and unlike previous research, it will explore the interaction between all three sensory modalities to find multisensory integration effects on the perception of acceleration.