This report presents the current knowledge about human behaviour in highly and fully automated vehicles and the psychological processes that influence task execution before, during and immediately after transition of control. The report also contains suggestions for further research and recommendations for policymakers. The dominant paradigm is the human factors paradigm. This paradigm focuses on human information processing. While driving in the fully automated mode, drivers will experience a loss of situation awareness, due to a low workload in which not much information related the driving task has to be processed. This diminished situation awareness will not be immediately reactivated after drivers have switched to manual driving. Indeed, a multitude of studies have indicated that diminished situation awareness occurs when task demands regarding the driving task are low, due to the automatization of the driving task.