DRIVING ASSISTANCE DEVICE AND DRIVING ASSISTANCE METHOD

A driving assistance device includes a determination unit that determines whether a brake light of a preceding vehicle located in front of a vehicle is turned on, based on a lighting state of a headlight of the preceding vehicle and an acceleration/deceleration of the preceding vehicle, a calculation unit that calculates a target acceleration/deceleration of the vehicle, based on a determination by the determination unit of whether the brake light of the preceding vehicle is turned on, and a control unit that controls the vehicle so that an acceleration/deceleration of the vehicle corresponds to the target acceleration/deceleration.