1. Notwithstanding section 310.4, if the board of supervisors of a county does not plan to utilize its farm-to-market road fund allocation for the succeeding fiscal year for farm-to-market projects, the board may annually, by stipulation in the secondary road construction program and secondary road budget submitted to the department in accordance with sections 309.22 and 309.93, determine an amount of the unobligated portion of its allocation, up to a maximum of fifty percent of its anticipated total annual allocation, for the construction and reconstruction of local secondary roads. However, moneys from the farm-to-market road fund shall not be so used if the moneys are needed to match federal funds available for farm-to-market road projects.
 2. A county shall not use farm-to-market road funds as described in this section unless the total funds that the county transferred or provided during the prior fiscal year pursuant to section 331.429, subsection 1, paragraphs “a”, “b”, “d”, and “e”, are at least seventy-five percent of the sum of the following:

 a. From the general fund of the county, the dollar equivalent of a tax of sixteen and seven-eighths cents per thousand dollars of assessed value on all taxable property in the county.
 b. From the rural services fund of the county, the dollar equivalent of a tax of three dollars and three-eighths of a cent per thousand dollars of assessed value on all taxable property not located within the corporate limits of a city in the county.