DRIVING ASSISTANCE DEVICE, METHOD, AND COMPUTER-READABLE NON-VOLATILE STORAGE MEDIUM

A driving assistance device, which is to be mounted on a vehicle capable of communicating with another vehicle, comprises a calculation unit configured to calculate a travel route of the another vehicle based on a communication result with the another vehicle, an arithmetic processing unit configured to determine whether the self-vehicle will interfere with the another vehicle traveling on the travel route calculated, and to generate a notification signal for giving a notification that the self-vehicle will interfere with the another vehicle, upon determination that the self-vehicle will interfere with the another vehicle, and an identification unit configured to identify a state of a shift range of the self-vehicle, wherein in a case where the shift range identified by the identification unit suppresses a movement of the self-vehicle, the arithmetic processing unit is deactivated.