La. Const. art. VII, § 5

The legislature shall impose an annual license tax of not more than one dollar per each one thousand dollars of actual value on automobiles for private use based on the actual value of the vehicle, as provided by law. However, the annual license tax shall not be less than ten dollars per automobile for private use. On other motor vehicles, the legislature shall impose an annual license tax based upon carrying capacity, horsepower, value, weight, or any of these. After satisfying the requirements of Section 9(B) of this Article, and after satisfying pledges respecting that portion of the revenues attributable to the tax rates in effect at the time of such pledges for the payment of obligations for bonds or other evidences of indebtedness and upon the creation of a Transportation Trust Fund within this constitution, the revenues from the license tax on automobiles for private use shall be deposited therein. In the event no such trust fund is established in this constitution, the revenues shall be used exclusively and solely as provided by law for the construction, maintenance, and safety of the federal and state system of roads and bridges, for the parish and municipal road systems, for the operations of the office of state police, Department of Public Safety and Corrections or its successor, and for the payment of any obligation for bonds issued or indebtedness incurred in connection with any of the foregoing, which bonds may be issued as revenue bonds under Article VII, Section 6(C) of this constitution, subject to existing pledges only as to that portion of the tax collections attributable to the rates in effect at the time of such pledges for the payment of any obligations for bonds or other evidences of indebtedness outstanding on the effective date of this Section. No parish or municipality may impose a license fee on motor vehicles.