A runway over which can travel vehicles driven by gravity, comprising a supporting structure and a track line structure sustained by the supporting structure and extending from a upper start region to a lower arrival region, wherein the supporting structure is limited to a central region of the runway by forming a pillar, and the track line structure includes some track line sections directly connected to the supporting structure and several overhanging track line sections of large extent, which project out of the supporting structure and are sustained by the same by means of rigging systems whose extension can be regulated; these rigging systems establish the geometrical location of the overhanging track line sections. In the embodiments intended to be used as games, the structures are embodied by the composition of systems of composable modular elements, which moreover allow to realize non-suspended runway structures, and which are compatible and integrated with a general system of composable elements, preferably the system of composable elements according to the U.S. Pat. No. 6,315,628.