Tenn. Code Ann. § 54-10-102: Power of county legislative body

The county legislative body has the power to build, repair, and maintain bridges and highways, and pay for the building, repair, and maintenance of bridges and highways out of general county funds, and, through commissioners and a superintendent of the county jail or workhouse, has the power to work certain inmates upon any public highway, with the aid and superintendence of the local commissioner and overseer, or independently of them.