California Code, Revenue and Taxation Code - RTC § 11051

(a) In addition to any other fee imposed on a vehicle by this code or the Vehicle Code, a transportation improvement fee is hereby imposed on each vehicle as defined in subdivision (c) of Section 11050 effective on January 1, 2018, or as soon after that date as the department is able to commence collection of the fee. The transportation improvement fee shall be in the amounts specified in Section 11052.

(b) The department shall collect the fee at the same time and in the same manner as the department collects the vehicle registration fee pursuant to Section 9250 of the Vehicle Code.

(c) The fee imposed pursuant to this chapter is imposed for the privilege of a resident of California to operate upon the public highways a vehicle or trailer coach, the registrant of which is subject to the fee under Chapter 2 (commencing with Section 10751).

(d) The revenues from the transportation improvement fee imposed by this chapter shall be available for expenditure only on transportation purposes as provided in Section 11053.