The examiners shall: open the bids at the time and place specified in the advertisement required under § 12–611 of this subtitle; and award the contract for bridge building or repair to the lowest bidder that meets the requirements of the notice. The person awarded the contract under subsection (a) of this section shall provide the governing bodies of the counties a bond issued by an approved surety, in double the amount of the contract, conditioned on performance of the contract. At any time during the performance of the bridge construction or repair, the examiners may inspect and direct the progress of the work. On completion of the bridge construction or repair, the examiners shall: take control of the bridge and open the bridge for public travel; and notify the governing bodies of the adjoining counties of the completion. On notification that the bridge building or repair is complete, the governing bodies of the adjoining counties shall pay their respective portions of the cost of the work according to the contract. If the examiners cannot agree on the portion of the cost of building or repairing the bridge each of the adjoining counties should pay, each group of examiners from each of the adjoining counties shall appoint an arbitrator to determine the amounts. If the arbitrators cannot agree on the portion of the cost of building or repairing the bridge each of the adjoining counties should pay, the arbitrators shall appoint an umpire to decide the portion of the cost each county must pay. The umpire may not reside in either of the adjoining counties. The decision of the arbitrators or the umpire is final and binding on the adjoining counties.