Subway vs. Underpass
“Underpass” refers to a passage or road going underneath another route. “Subway” can mean that kind of pedestrian passage in British English, but mainly means an underground urban railway in American English.
Use “underpass” for the general passage sense; remember that “subway” often means an underground railway in US English.
Key details
Further guidance
Core difference
“Underpass” is the unambiguous general term for a road or path passing underneath something. “Subway” has a regional split: UK passage sense versus mainly-US rail sense.
Fast Test
If international readers could mistake the passage for a rail system, prefer “underpass.”
Usage Boundary
A US “subway” normally means an underground city railway, not simply a pedestrian underpass.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Subway — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Direct evidence for the mainly-US rail sense and the UK pedestrian-underpass sense of “subway.”
- Underpass — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Direct definition of an underpass, noting UK “subway” as an alternative for the passage sense.