A transportation authority is an authority which regulates or administers transportation related matters. Most transportation authorities in Western countries are under the direction of elected officials.
In the United States and Canada, transportation authorities are typically responsible for public transit including buses and rapid transit in metropolitan areas, such as the Metropolitan Transportation Authority in New York, the Los Angeles County Metropolitan Transportation Authority, and the Toronto Area Transportation Operating Authority.
Some transportation authorities, such as Greater Vancouver's Translink, have the power to impose excise taxes (fuel taxes) on gasoline, diesel fuel, and other motor fuels.
References
Transportation authority Wikipedia(Text) CC BY-SA