A driving assist apparatus 1 that performs driving assist on the basis of a traffic rule of a mobile object includes a traffic rule acquisition unit 11, 12, and 13 acquiring a traffic rule which a mobile object is highly likely to observe in an arbitrary region, and performs driving assist on the basis of the traffic rule acquired by the traffic rule acquisition unit. In particular, the driving assist apparatus includes a region acquisition unit 13 acquiring a traffic rule deviation region where a defined traffic rule in an arbitrary region does not conform to the traffic rule acquired by the traffic rule acquisition unit, or a traffic rule correction unit correcting the traffic rule acquired by the traffic rule acquisition unit when a defined traffic rule in an arbitrary region does not conform to the traffic rule acquired by the traffic rule acquisition unit.