The purpose of this study is to examine the degradations of driving and talking performances due to interferences of semantic and spatial information processing during dual task performances between cell phone talk and driving. The color and geographical information fed into the ears through the cell phone is classified into semantic and spatial information in cerebral activities, respectively. The information regarding traffic signal and road scene perceived by the eyes in driving task is similarly classified. The interferences due to the combinations of their information were experimentally investigated using a driving simulator. Traveling instability and time lag of braking operation were measured as well as reaction time of listening task while driving. As a result, degradations of driving performances and reactions to listening task became more distinguished in case the same kind of information both from visual and auditory organs was processed simultaneously.