The county commissioners shall submit to the auditor a detailed statement showing all new road and bridge construction to be financed from the county road fund, and from bond issues theretofore issued, if any, for the ensuing fiscal year, together with the cost thereof as computed by the county road engineer or for constructions in charge of a special engineer, then by such engineer, and such engineer shall prepare such estimates of cost for the county commissioners. They shall also submit a similar statement showing the road and bridge maintenance program, as near as can be estimated.

The county commissioners shall also submit to the auditor detailed estimates of all expenditures for construction or improvement purposes proposed to be made from the proceeds of bonds or warrants not yet authorized.