a structure built to span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the way underneath [wikipedia].<br/>
tunnel
Public
Notes:
underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end [wikipedia].<br/>
movableBridge
Public
Notes:
A special movable bridge (undercrossing) which is used for railway traffic passing a waterway underneath the railway line in normal position but allows for temporarily being moved out of the way of the vessels. It is then not passable by trains.<br/>The normal position is locked and supervised by interlocking system. The other control of the bridge is outside the interlocking system.<br/><br/>
