A vehicle travel support device determines presence of a recognition inhibiting factor of a lane mark on a road on which a vehicle is traveling with high accuracy irrespective of an imaging history by a vehicular camera from the same position. The vehicle travel support system generates an edge image by extracting an edge or actualizing an edge in an image obtained through the vehicular camera. When Hough transform of the edge image is performed, votes for a specified vote value of a linear component is evaluated in a ρ-θ space (Hough space). Presence of a recognition inhibiting factor of a lane mark on a road is determined by determining whether or not the votes of a specified vote value in a specified region denoting a standard travel lane of a vehicle in the real space is ≧a threshold in the ρ-θ space.