DECELERATION ASSISTANCE DEVICE, VEHICLE, DECELERATION ASSISTANCE METHOD, AND PROGRAM

A deceleration assistance device including: a target information acquisition unit for acquiring information of a target located in front of a vehicle; a position estimation unit for estimating an estimated position of a deceleration object; a position recognition unit for recognizing a position of the deceleration object; and a control unit for executing, based on the estimated position, first deceleration control of decelerating a vehicle at a first deceleration and executing, based on the recognized position, second deceleration control of decelerating the vehicle at a second deceleration. The control unit executes processing of gradually changing a deceleration of the vehicle from the first deceleration toward the second deceleration when the deceleration control is caused to transition from the first to the second deceleration control, and when a difference exists between the first and second deceleration.