Rev. & Tax. Code, § 60039

(a) “Exempt bus operation” consists of the following:

(1) Any transit district, transit authority, city, or county owning and operating a local transit system itself or through a wholly owned nonprofit corporation.

(2) Any private entity providing transportation services for the transportation of people under contract or agreement, except general franchise agreements, with a public agency authorized to provide public transportation services, only for diesel fuel consumed while providing services under those contracts or agreements entered into subsequent to January 1, 1979.

(3) Any passenger stage corporation subject to the jurisdiction of the Public Utilities Commission when the motor vehicles of the passenger stage corporation are exclusively operated in urban or suburban areas or between cities in close proximity for the transportation of persons for hire, compensation, or profit. However, the exemption is not extended to any line or lines operated by the passenger stage corporation that exceed 50 miles of one-way route mileage.

(4) Any common carrier of passengers operating exclusively on any line or lines within the limits of a single city between fixed termini or over a regular route, 98 percent of whose operations, as measured by total route mileage operated, are exclusively within the limits of a single city, and who by reason thereof is not a passenger stage corporation subject to the jurisdiction of the Public Utilities Commission.

(5) Any school district, community college district, or county superintendent of schools owning, leasing, or operating buses for the purpose of transporting pupils to and from school and for other school or college activities involving pupils, including, but not limited to, field trips and athletic contests.

(6) Any private entity providing transportation services for the purposes specified in paragraph (5) under contract or agreement with a school district, community college district, or county superintendent of schools, only for diesel fuel consumed while providing services under those contracts or agreements entered into subsequent to September 30, 1984.

(b) “Exempt bus operation” as defined in subdivision (a), shall not be applicable to a charter-party carrier of passengers. The term “charter-party carrier of passengers” has the same meaning as that specified in Section 5360 of the Public Utilities Code and shall further include those transportation services described in subdivisions (a) and (e) of Section 5353 of the Public Utilities Code, if that transportation service is rendered as contract carriage and not as common carriage of passengers.