Tennessee Code Title 54. Highways, Bridges and Ferries § 54-9-118

When all road commissioners have been elected, they shall be the road commissioners for that county, and shall have the supervision of the construction of the roads provided for by the county legislative body, and shall serve until all the roads so provided for have been completed according to the specifications laid out by the county legislative body, or until all the money provided for under the bond issue for the county has been expended on the roads of the county.