The Georgia Regional Transportation Authority or GRTA (pronounced like the name "Greta" when referring to Xpress operations. Pronounced G.R.T.A. when referring to the authority) is a government agency in the U.S. state of Georgia. It was set up under former governor of Georgia Roy Barnes, in order to address mobility, air quality and land use and how they relate to the transportation needs of metro Atlanta, including both roads and public transit. It came about in large part because the numerous cities and counties in the region could not effectively (or would not at all) work with each other to achieve a comprehensive solution to the area's traffic woes, and increasing summertime smog problems. - Source: Wikipedia