In England, if the land for the road was not bought by the highway authority, the boundary of the adjoining land is the centre of the road, so you are always on someone's property, especially if the land on both sides of the road belongs to the same person or entity. Provided you do not cause distress or hinderance to anybody using the highway, you can shoot from a road onto your land. We have shot loads of foxes from the roads through the estate I help out on.