For example, JP2015-110417A discloses a drive assistance device that increases a degree of assistance of a driving operation (e.g., a degree of assistance when parking) when a driving skill of a vehicle driver is insufficient against a required level corresponding to an environmental difficulty based on an outside environment.
However, since it is difficult to accurately estimate the driving workload (e.g., environmental difficulty) and the driving skill with the drive assistance device, suitable drive assistance may not be provided.