Upon the approval of such plans and specifications by the state road commissioner, the railroad company affected shall secure sealed bids for the construction of such work, and within thirty days after the approval of such plans shall receive and open such bids, after having notified the road commissioner five days in advance of the day on which such bids shall be opened. The work shall be let to the lowest responsible bidder, subject to the provisions hereinafter contained. The successful bidder shall be required to prosecute the work to completion with reasonable diligence.
W. Va. Code § 17-4-13