It is hereby declared by the Legislature of the State of Mississippi that railroad transportation and commerce is essential to the economic well-being of the state and the development of its natural resources and its agriculture and industry, and the preservation, development and maintenance of the state’s rail service is in the public interest and serves a public purpose. It is the intent of the Legislature by this chapter to provide the manner and means necessary to carry out such purposes. The exercise of the powers granted in this chapter to the authorities and other public bodies is hereby declared to be a public and governmental function for a public purpose and public necessity.