American Public Transportation Association

The American Public Transportation Association (APTA) is a nonprofit group of approximately 1,500 public and private sector member organizations that promotes and advocates for the interests of the public transportation industry in the United States. APTA represents all modes of public transportation, including bus, paratransit, light rail, commuter rail, subways, waterborne services, and intercity and high-speed passenger rail.

Source: Wikipedia — American Public Transportation Association (CC BY-SA 4.0)