(1) commercial motor vehicles, both bus and truck, and their control, regulation, licensing, and operation; (2) the Texas highway system, including all roads, bridges, and ferries constituting a part of the system; (3) the licensing of private passenger vehicles to operate on the roads and highways of the state; (4) the regulation and control of traffic on the public highways of the State of Texas; (5) railroads, street railway lines, interurban railway lines, steamship companies, and express companies; (6) airports, air traffic, airlines, and other organizations engaged in transportation by means of aerial flight; (7) water transportation in the State of Texas, and the rivers, harbors, and related facilities used in water transportation and the agencies of government exercising supervision and control thereover; (8) the regulation of metropolitan transit; and (9) the following state agencies: the Texas Department of Motor Vehicles, the Texas Department of Transportation, and the Texas Transportation Commission.