Nevada constitution
Article 9: finance and state debt
Section 5

The proceeds from the imposition of any license or registration fee and other charge with respect to the operation of any motor vehicle upon any public highway in this State and the proceeds from the imposition of any excise tax on gasoline or other motor vehicle fuel shall, except costs of administration, be used exclusively for the construction, maintenance, and repair of the public highways of this State. The provisions of this section do not apply to the proceeds of any tax imposed upon motor vehicles by the Legislature in lieu of an ad valorem property tax.