Provided is a driving assistance device for assisting a driver in a vehicle to drive, said device comprising: an information acquisition unit (51) for acquiring detection information for another vehicle (Ao) traveling in the periphery of the host vehicle (As) proper; a computation unit (53) for computing, as a risk estimation value, the risk posed by the other vehicle to the host vehicle on the premise that the other vehicle not presently on the intended route of progress (P) of the host vehicle will move onto the intended route of progress and using the detection information pertaining to the lateral position of the other vehicle relative to the host vehicle; and a selection unit (54) for selecting a driving assistance prescription corresponding to the risk estimation value computed by the computation unit.
DRIVING ASSISTANCE DEVICE AND DRIVING ASSISTANCE PROGRAM