For higher loadings, the Stilt Tunnel is used in the verge with ACO Climate Tunnels in the carriageway, either installed at road surface level for a slotted tunnel, in which case the tunnel floor needs to be ramped at the entrances, or installed below road surface level using solid top units, giving a constant floor level.

In these cases a Stepdown unit bridges the gap between the differing heights of the system components.

The ACO Climate Plate, complete with drain holes, is used to form a floor in the same material as the ACO Climate Tunnel, providing a uniform surface for animals to move along.

No metal reinforcement is used, so animals are not disoriented by distortion of magnetic fields, while the non-absorbent surfaces has minimal thermal conductivity, providing an ideal surface for amphibians to move along.