In this subtitle the following words have the meanings indicated. “Approach” means any roadway, overhead structure, ramp, bridge, causeway, entrance, and exit provided as a means of access to or departure from an Authority highway. “Authority highway” means: Each highway, tunnel, and bridge within the jurisdiction of the Maryland Transportation Authority; and Each approach to these highways, tunnels, and bridges. “Bridge” means any bridge within the jurisdiction of the Maryland Transportation Authority. “Tunnel” means: The Baltimore Harbor Tunnel; and Any other tunnel within the jurisdiction of the Maryland Transportation Authority.