Patent ID: 8346427

Claim:
A vehicle travel support device comprising a first processing element configured to recognize the presence and the disposition of a lane mark on a road where a vehicle is traveling according to an image of the road obtained through an imaging device mounted on the vehicle and recognize a travel area demarcated by a left lane mark and a right lane mark disposed with a separation in the width direction of the road; and a second processing element configured to control an operation of a steering device or a braking device mounted in the vehicle to prevent the vehicle from departing from the travel area recognized by the first processing element, wherein the first processing element is configured to recognize a virtual travel area as the travel area when a first condition is satisfied, the first condition is a condition in which the separation between the left lane mark and the right lane mark in the width direction of the road exceeds an expected width at a predetermined distance in front of the vehicle, the virtual travel area is demarcated by one of the left lane mark and the right lane mark used as a reference lane mark extending along an intended travel road for the vehicle at a first side thereof and a virtual lane mark disposed with a separation from the reference lane mark in the width direction of the intended travel road at a second side thereof, the first processing element is further configured to recognize the virtual travel area as the travel area when a second condition is satisfied, and the second condition is a condition in which at least one requirement of a set of requirements is satisfied, wherein the set of requirements includes: a curvature of the reference lane mark being equal to or smaller than a first threshold around a point where the first condition is satisfied, the rate of change of the curvature being equal to or smaller than a second threshold around the point where the first condition is satisfied, and a deviation from the reference lane mark in the width direction of the road being equal to or smaller than a third threshold around a point where the first condition is satisfied.