The work of repairing and maintaining said road, or sections thereof, subsequent to the putting of the same in condition as provided in section three,¹ may be done by contract, let to the lowest responsible bidder, after thirty days' advertisement for proposals, in at least two newspapers of the county wherein the work is to be done; or the state highway department may do any such work itself, purchasing the necessary materials and appliances, and hiring the necessary labor, at the current rates for similar materials, appliances and labor. For the purpose of having the repair, maintenance, and care of said road properly supervised, the state commissioner of highways may employ not more than two superintendents, at a salary not to exceed one thousand dollars per annum, and assign to each of them the portion or portions of said road to be under his care. Said superintendents shall in all things be subject to the orders and direction of said commissioner.