It should be capitalized if you are referring to a specific metro system.
Noida is not a metro City
Metro La Paz - Mexico City Metro - was created in 1991.
In kerala, no city is approved as a real metro. But, Kochi and Trivandrum are the cities eligible for a metro
Mexico City Metro was created in 1969.
Mexico City Metro Line A was created in 1991.
Yes! Capitalize all proper nouns, including cities.
no
Mexico City Metro Line B was created in 1999.
The name of a city should be capitalized but 'city' shouldn't be.
The Vatican has no metro. However, the Rome Metro comes very close to the Vatican.
no. Metro runs only in New Delhi and Kolkata.