John Rowland writes
Also, here in the UK we tend to use the word "subway"
to describe a pedestrian underpass beneath a road,
rather than an underground railway system.

No: in Glasgow the underground railway is referred to by most people as
"The Subway". In London "subway" can only mean a pedestrian underpass.

Er, he did say 'tend to use' - not 'exclusively use'.

In Glasgow, the system's official name has only recently reverted to
being the 'Subway' after more than 20 years of officially being the
'Underground'

--
Dave