In a fully Autonomous Vehicle (AV), what activities could be performed when travelling to replace driving activity? The ideal would be to do activities similar to those done in a train or at home. This paper reviews the existing literature to compare the activities expected in an AV with findings obtained for trains and cars. It focuses on a selection of 36 papers mainly on transport economics published between 2000 and 2021. The findings show that train users are more multitask than others. They do several activities of which reading and sleeping are the most popular. Car travellers perform fewer activities other than driving except for making phone calls and listening to music. For AVs, the first studies show that future users would be more in the position of a car driver than a train passenger, thereby reducing the benefit of AVs. Finally, the analysis reveals heterogeneity in the definition of activities and imperfect consistency with the characteristics of AVs. We suggest considering physical involvement (hands and eyes), whether deliberate or not, to define an activity. Sleeping becomes an active activity and talking a passive activity.