From OpenStreetMap Wiki
| railway = subway
|city passenger rail service|
|Used on these elements|
|Tools for this tag|
Type of railway track for a city passenger rail service (see Rapid transit).
How to Map
Tags to use in combination
- tunnel=yes for underground sections and...
- tunnel=no for overground sections (note that it is useful to set this to dispel any ambiguity in the case of railway=subway ways)
- electrified=rail - Indicates infrastructure to supply vehicles with electricity
- gauge=# - Gauge in mm
- frequency=# - Frequency in Hz
- voltage=# - Voltage in Volt
To map the route of the subway