Physical Structures:
* Span: A general term for a structure that crosses a gap.
* Viaduct: A bridge supported by a series of arches or piers.
* Overpass: A bridge carrying a road over another road or railway.
* Causeway: A raised road or path across water or low-lying land.
* Aqueduct: A bridge-like structure carrying a canal or water pipe.
* Passerelle: A footbridge, especially a narrow one.
Figurative Meanings:
* Connection: A link or relationship between two things.
* Mediator: Someone who helps two parties to communicate and reach an agreement.
* Passage: A means of transition or movement from one state to another.
* Link: A connection or relationship between two things.
* Connecting point: A place or thing that joins two things together.
* Intermediary: Someone who acts as a go-between.
* Transition: A process of change from one state to another.
Other:
* Crossing: A general term for any structure that allows people or vehicles to cross a barrier.
* Passageway: A narrow passage or corridor.
To choose the best synonym, consider the specific context of your sentence.