Fla. Const. art. VII, § 17

(a) When authorized by law, state bonds pledging the full faith and credit of the state may be issued, without a vote of the electors, to finance or refinance the cost of acquiring real property or the rights to real property for state roads as defined by law, or to finance or refinance the cost of state bridge construction, and purposes incidental to such property acquisition or state bridge construction.

(b) Bonds issued under this section shall be secured by a pledge of and shall be payable primarily from motor fuel or special fuel taxes, except those defined in Section 9(c) of Article XII, as provided by law, and shall additionally be secured by the full faith and credit of the state.

(c) No bonds shall be issued under this section unless a state fiscal agency, created by law, has made a determination that in no state fiscal year will the debt service requirements of the bonds proposed to be issued and all other bonds secured by the same pledged revenues exceed ninety percent of the pledged revenues available for payment of such debt service requirements, as defined by law. For the purposes of this subsection, the term “pledged revenues” means all revenues pledged to the payment of debt service, excluding any pledge of the full faith and credit of the state.