DRIVING ASSISTANCE DEVICE AND DRIVING ASSISTANCE SYSTEM

An object of the present invention is to realize lane deviation warning/control at an intersection, on a multilane road and in an environment where no lane dividing lines are present and GNSS accuracy is low. A driving assistance device includes a recording unit that records a plurality of past traveling positions of a vehicle and position estimation information relating to the past traveling positions, a relative position estimation unit that estimates a relative position of the vehicle from an output of a sensor that detects a surrounding of the vehicle, adds a history of the relative position to the past traveling position, and adds the output of the sensor, which is used to estimate the relative position, to the position estimation information, a position estimation unit that estimates a position of the vehicle with respect to the past traveling positions from the output of the sensor and the position estimation information of the recording unit, and adds a history of the estimated position to the past traveling position, a deviation determination unit that determines deviation from the plurality of past traveling positions by using a distribution of the plurality of past traveling positions, the position of the vehicle with respect to the plurality of past traveling positions, and a predetermined reference value, and a control unit that controls the vehicle to cancel a warning or deviation, when the deviation is determined.