Cal. Pub. Util. Code § 24561

Any city together with unincorporated territory, or two or more cities, with or without unincorporated territory, in either Alameda County or Contra Costa County or both, may organize and incorporate as a transit district. Cities and unincorporated territory included within a district may be in the same or separate counties and need not be contiguous. No city shall be divided in the formation of a district. A city may be in more than one transit district formed under this division.

It is necessary that a district be formed in Alameda and Contra Costa Counties to meet the transit problem, for the area involved covers more than one city and is in two counties; moreover, the problem is unique to these counties due to their geographic location in relation to the centers of employment of many of their residents. Although a municipal utility district could provide transportation facilities, there is already an existent municipal utility district in part of the area which provides water and sewage disposal to persons who will not necessarily be benefited by the transportation facilities, and if a new municipal utility district is formed, there is a possibility of its becoming merged by operation of law with the existent district, which would result in those persons in the existent district being inequitably taxed to pay for the transit facilities and those benefited only by the transit facilities being taxed to support the water and sewage disposal functions of the district.

Also, there are existing transportation facilities in the area which may be taken over by the transit district and special provisions relating to this transfer and to the employees of these facilities, as provided for by this division, are necessary to protect the public interest.