All vehicles commonly called automobile buses or other self-propelled vehicles carrying passengers for hire within the City shall be governed by the provisions of this chapter; provided, that taxicabs kept and maintained as such at all times and operated strictly within the usual functions thereof, and automobile vehicles carrying passengers for hire and operating over a regular route and between fixed termini under a certificate of convenience and necessity from the State Corporation Commission shall not be subjected to the provisions of this chapter. Any person carrying or offering to carry any passenger for hire under the provisions of this chapter is hereby declared to be a common carrier of passengers. (Code 1981 § 46-88. Code 1995 § 154-151.)