California Code, Public Utilities Code - PUC § 99420

(a) Notwithstanding any other provision of law, a transit operator may enter into agreements with a public agency, public utility, or person or entity, to be performed within the district, or a transportation corridor or land that shall be acquired by the transit operator, for the joint use or joint development of any property or rights of the transit operator or of the public agency, public utility, or person or entity for the establishment of through routes, joint fares, transfer of passengers, pooling rights, sales or leasing, or for any other purpose necessary for, incidental to, or convenient for, the full exercise of the powers granted to transit operators.

(b) As used in this section, the following terms have the following meanings:

(c) The purpose of any joint development project entered into in accordance with this section shall be to foster transit use, enhance the transit service, or foster the integration of land use and transportation.

(d) For purposes of this section, a transit operator is prohibited from engaging in agreements unrelated to the transportation purposes and mission of the transit operator.

(e) Any transit oriented joint development project undertaken pursuant to this section shall comply with the land use and zoning regulations of the city, county, or city and county in which the project is located in accordance with the Planning and Zoning Law (Chapter 1 (commencing with Section 65000) of Division 1 of Title 7 of the Government Code) relating to zoning.

(f) This section shall not supersede any existing authority of a transit operator for joint development.