348.53 Purposes of the authority.—The authority is created for the purposes and shall have power to construct, reconstruct, improve, extend, repair, maintain and operate the expressway system. It is hereby found and declared that such purposes are in all respects for the benefit of the people of the State of Florida, the City of Tampa, and the County of Hillsborough for the increase of their pleasure, convenience, and welfare; for the improvement of their health; and to facilitate transportation, including managed lanes and other transit supporting facilities, for their recreation and commerce and for the common defense. The authority is performing a public purpose and a governmental function in carrying out its corporate purpose and in exercising the powers granted herein.