Disclosed is a driving assistance method, comprising: periodically capturing an image in front of a vehicle; obtaining fitting points on each of edges of a road in the image; generating a virtual boundary on the basis of the obtained fitting points; and generating at least one virtual lane line between two virtual boundaries of the road. With the driving assistance method, the road without lane division can be divided into lanes to improve traffic safety. The present disclosure also provides a driving assistance device and a vehicle having the same.