This vehicle travel safety device improves the recognition accuracy of road shapes while preventing an extreme increase in the computation amount required for correction of road data. An inactive determination portion determines that the operating portion is inactive when a safety device does not operate for an estimated curve that is estimated by a curve estimating portion and also deceleration of a predetermined amount or more occurs by a deceleration operation of the driver before entering the estimated curve or while traveling through it, or when a safety device does not operate for an estimated curve that is estimated by a road shape estimating portion and also the vehicle condition of the self-vehicle is not in the proper vehicle condition to be able to properly pass the estimated curve. The data correcting portion changes the road data of the storage portion that is used in the detection of the recognized curve shape that corresponds to this estimated curve so as to facilitate operation of the operating portion at the estimated curve where the operating portion is determined to be inactive by the inactive determination portion, or adds new road data to the storage portion.