A spreading device for confined application of grain type materials along a well-defined path on a road from a conveyor of a storing tank mounted on a moving vehicle includes a chute member mounted thereon that receives the materials from the conveyor and substantially drops them generally vertically under gravity on the road along the path in proximity and in front of a roller. The latter stops the materials relative to the road and confines, or packs, them on the road. The spreading device is adapted to be mounted on either side of the vehicle, in line with its wheels.