California Code, Education Code - EDC § 39800

(a) The governing board of any school district may provide for the transportation of pupils to and from school whenever in the judgment of the board the transportation is advisable and good reasons exist therefor. The governing board may purchase or rent and provide for the upkeep, care, and operation of vehicles, or may contract and pay for the transportation of pupils to and from school by common carrier or municipally owned transit system, or may contract with and pay responsible private parties for the transportation. These contracts may be made with the parent or guardian of the pupil being transported. A governing board may allow the transportation of preschool or nursery school pupils in schoolbuses owned or operated by the district. A state reimbursement may not be received by a district for the transportation of preschool or nursery school pupils.

(b) As used in this article, “municipally owned transit system” means a transit system owned by a city, or by a district created under Part 1 (commencing with Section 24501) of Division 10 of the Public Utilities Code.