California Code, Public Utilities Code - PUC § 732

(a) Whenever the commission, after a hearing finds that the rates, fares, or charges in force over two or more common carriers, between any two points in this state, are unjust, unreasonable, or excessive, or that no satisfactory through route or joint rate, fare, or charge exists between such points, and that the public convenience and necessity demand the establishment of such a through route and joint rate, fare, or charge, the commission may order such common carriers to establish such through route and may establish and fix a joint rate, fare, or charge which will be fair, just, reasonable, and sufficient, to be charged and collected in the future, and the terms and conditions under which such through route shall be operated. The commission may order that freight moving between such points shall be carried by the common carriers participating in such through route and joint rate, without being transferred from the originating cars.

(b) Subdivision (a) is not applicable to network railroad transportation.