The phrase "a metro system" is correct and usable in written English
It can be used when referring to an urban public transportation system that operates trains or subways.
Example: "The city has invested heavily in developing a metro system to reduce traffic congestion."
Alternatives: "a subway system" or "an underground transit system"
Delhi Metro is a metro system serving Delhi (including New Delhi and Old Delhi) and its satellite cities of Gurgaon, Noida, Faridabad and Ghaziabad in the National Capital Region of India.
Mashhad also began constructing a metro system, the first line of which opened in 2011.
Work will start on a metro system for the capital, Bogotá, before the end of the year.
A metro system, is being built in Los Teques, outside Caracas, and in the capital the subway is being expanded.
So in 2004, construction began on a metro system that would run through a tunnel on the sea floor of the Bosphorus Strait.
A rail network, a metro system, a new network of roads and an entire new city are to be constructed over the next eight years.
The recently opened Rapid MetroRail Gurgaon, whilst linked to it by the Yellow Line is a separate metro system (with a different owner/operator than the Delhi Metro), although tickets from the Delhi Metro can be used in its network.
Councillor Graham Hinchey, cabinet member for strategic planning and transport, said a regional metro system was a "proven and demonstrable" way of getting commuters out of cars, as shown in Manchester and Nottingham.
Unable to finance a full metro system, Bogota, Colombia has had a BRT system for more than a decade that handles 1.9 million passengers per day.
Ms Hutt announced a series of capital spending commitments, including: Transport: £62m for phase one of a new scheme to create a South East Wales metro system through better bus and rail links.
Supporters say that when the project is completed there will be new housing, a ring road, parking lots and a new metro system.
