1. County commissions shall cause to be set aside and placed to the credit of each road district so incorporated four-fifths of such part or portion of the tax arising from and collected and paid upon any property lying and being within any such district, by authority of section 137.555. All revenue so set aside and placed to the credit of any such incorporated district shall be used by the commissioners thereof for constructing, repairing and maintaining bridges and culverts within the district, and working, repairing, maintaining and dragging public roads within the district and paying legitimate administrative expenses of the district, and for such other purposes as may be authorized by law.

2. In any county of the first class not having a charter form of government or of the second or third class containing all or part of a city having a population of three hundred fifty thousand or more, the revenue set aside and credited to a road district as provided in subsection 1 may, with the consent of the city, be expended within any incorporated city, town or village located within the district.