(a) No refund of any tax shall be granted on motor vehicle fuel used in propelling passenger carrying vehicles, except six cents ($0.06) of the tax imposed upon each gallon of motor vehicle fuel used in propelling passenger carrying vehicles used for the transportation of persons for hire, compensation, or profit of the following:

1. (1) Any transit district, transit authority, or city owning and operating a local transit system itself or through a wholly owned nonprofit corporation.
2. (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, including, but not limited to, any nonprofit corporation designated as a consolidated transportation service agency pursuant to subdivision (a) of Section 15975 of the Government Code, which provides door-to-door transportation services under contract or agreement with a transit district, transit authority, or public agency authorized to provide transportation services, but only for fuels consumed while providing services under those contracts or agreements entered into subsequent to the effective date of this act.
3. (3) Any passenger stage corporation subject to the jurisdiction of the Public Utilities Commission when the motor vehicles of such passenger stage corporation are exclusively operated in urban or suburban areas or between cities in close proximity; provided, however, that the exemption is not extended to any line or lines operated by such passenger stage corporation which shall exceed 50 miles of one-way route mileage.
4. (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.