Any county may establish and construct new roads, change or extend existing roads, and improve such roads by grading, surfacing, draining and incidental work by the board on its own initiative declaring the advisability or necessity therefor in a proposed resolution, which resolution shall state (1) the road or roads to be improved, (2) if a new road is contemplated, the general location of the new road or changes in location of an existing road, (3) the general description of the proposed improvement, and if the road is to be surfaced, the materials to be used therefor, (4) a rough estimate of the total cost of the improvement, which may be made by the county surveyor or any engineer or competent person and need not be based on detailed plans and specifications, (5) proposed method of financing, and (6) the outer boundaries of the district in which it is proposed to levy special assessments.