Wis. Stat. § 83.065: County road and bridge fund; tax levy.

The county board shall annually levy a tax of not more than 2 mills on the dollar, in addition to all other taxes, and the proceeds shall be known as the “County Road and Bridge Fund”. Expenditures from said fund shall be made only for the purposes of constructing and maintaining highways and bridges under this chapter and for purchasing, operating, renting and repairing machinery, quarries and gravel pits used in such construction and maintenance.