Cal. Pub. Util. Code § 30637
The district shall not exercise control over any transit facilities now or hereafter owned and operated wholly or partly within, or without, the district by any city or public agency, unless by consent of such city or public agency and upon such terms as are mutually agreed upon between the board and such city or public agency.
The district shall not establish, construct, complete, acquire, operate, extend, or reroute (all of the foregoing being hereinafter referred to by the word "establish" in all forms thereof), directly or indirectly, either itself or by lease or contract with any other person or otherwise, any rapid transit service or system in such manner or form as will or may, either then or at any time in the future, divert, lessen, or compete for the patronage or revenues of the existing system of a publicly or privately owned public utility without the consent of the public utility, if the existing system has been in operation since at least August 1, 1974.
The maintenance and operation, but not the extension or rerouting, of any existing system acquired by the district from a publicly or privately owned public utility shall not be deemed to be the establishment of a rapid transit service or system within the meaning of this section.
The construction by the district of any structures constituting a method of rapid transit, and the operation therein and thereon of any equipment except buses, shall not be deemed to be the establishment, construction, completion, acquisition, operation, or extension of rapid transit within the meaning of this section.
No publicly owned public utility shall establish, construct, complete, acquire, or extend, directly or indirectly, either itself or by lease or contract with any other person or otherwise, any rapid transit service system in such manner or form as will then substantially divert or reduce the patronage or revenues of the system operated by the district. Any municipality may acquire and operate any existing transportation system within its existing transit service area without being in violation of this paragraph and may make route extensions to such system within its existing transit service area where such extensions do not compete with the established services of the district.
Nothing in this part shall be construed as in any way preventing or restricting the City of Los Angeles or any other city from exercising any powers which it has under Section 9 of Article XI of the California Constitution, including, without limitation, the establishing and operation of any point to point lines or system of rapid transit to operate in connection with any other transportation services established and operated by such city.
Ca. Pub. Util. Code § 30637