(a) The county government shall award a contract or contracts for the required improvements upon a competitive basis pursuant to public advertisement of the intention of the county government to receive sealed proposals for the work on the improvements. In every respect, the letting of the contracts shall follow the practice of the Department of Transportation in letting the Department contracts.
(b) Upon the opening of the sealed proposals, the county government, after consultation with the Department, shall award the contract or contracts. No contract shall be awarded to any other than the lowest bidder except with the unanimous approval of the members of the county government and the recommendation of the Department of Transportation, and if a contract should be awarded to a person other than the lowest bidder, the county government shall state in its minutes the reason or reasons for doing so.
(c) As a condition of the letting of the contracts, the county government shall require the successful bidder or bidders to enter into a bond for the faithful performance of such contract.
(d) The county government shall have the power to reject all bids.