PURPOSE: To obtain a road detecting apparatus, wherein the resolution of the image of a road is made uniform regardless of the far and near of the road from a vehicle, and the coordinate conversion between the coordinate of the image and the coordinate of the road is readily performed.

CONSTITUTION: In a road detecting apparatus, the image of a road 3 around a vehicle 10 is picked with an image sensing element 12 through an optical system 11. Thus the image of the road is inputted into a road-image input device 1. A plurality of pixels 15 are arranged on two-dimensional coordinates. The pixels for picking up the image of the road 3 in the vicinity of the vehicle are coarsely arranged. When the vehicle 10 goes away far from the road 3, the pixels for picking up the image of the road 3 are more densely arranged gradually.