The term 'road-fork shape' refers to a type of intersection where two roads diverge in a V- or Y-shaped pattern. The two most common types of road-fork shapes are the VEE (3 letters) and the Wye (3 letters). A VEE is formed when two roads meet at an angle, while a Wye is formed when two roads meet at a point. Both types of road-fork shapes are used to create intersections that allow for smoother traffic flow.