[cmsmith]

In DC, the mass transit agency is usually referred to as Metro, and offers two main services - Metrorail and Metrobus.

[yardie]

I’ve only referred to the train as the metro and the buses as the bus. I’ve only seen in one city the locals refer to the train as the metrorail. And that was Miami.

[TheCoelacanth]

In colloquial use, you are right, but in written media I see references to DC Metrorail all the time.