Tenn. Code Ann. § 54-9-136: Expenditure of surplus on other roads

After all the roads laid out and provided for in the resolution have been graded, macadamized or otherwise improved for the full length of each road, should there remain a surplus, it shall be expended on such other road or roads not set forth in the resolutions, that in the judgment of the commissioners will serve the greatest number of people within the county.