Due to the increase in the level of automation of vehicles and according regulations by law, in the future it will be possible to turn towards other activities while driving automatically. These so-called non-driving related activities (NDRA) and their systematisation in combination with an initial suitability assessment in relation to the driver availability are the focus of this article. After presenting the structure of the developed suitability catalogue for the systematisation of suitable non-driving related activities at SAE Level 3 and Level 4 in heavy goods vehicles, the challenges in creating such a systematisation and the implications for practice are described.