A driving support device includes: a position detector; a traveling direction detector; a map data memory; a map matching element for matching a current position of a vehicle on a road of map data; a traveling segment estimation element for estimating a current segment of the vehicle in the parking place road when a matched road is the parking place road; a main road search element for determining whether a segment of a main road of an express way is disposed in a predetermined search distance from an estimated current segment; and a reverse run determination element for determining whether the vehicle travels reversely when the main road search element determines that the segment of the main road is disposed in the predetermined search distance from the estimated current segment.