A number of traffic accidents are due to decreasing of driver's vigilance level and this is a serious concern to society. Drivers sometimes have trouble in their perception, recognition, and vehicle-control abilities when their vigilance level is low. Then how about autonomous car? One of the major issues in automation is workload and a situation awareness. If the workload is too low, then the vigilance level is decreasing and situation awareness is also decreasing.

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In this research vehicle is mocked up as the autonomous vehicle which has level 4 of automation. The participants (autonomous vehicle driver) should attention to forward or do other tasks with