§ 30. General powers of board of transportation. The board of
transportation is empowered to operate any railroad acquired, owned,
constructed, or provided by such city in accordance with the provisions
of law. The board of transportation shall also be empowered to purchase
all necessary materials and supplies for such operation and maintenance,
and, generally, to exercise all requisite and necessary authority to
manage and direct the operation and maintenance of such road for the
convenience and safety of the public, provided, however, that, except as
otherwise provided in section seventeen of this chapter, any contract
for the purchase of such materials and supplies or work or labor to be
performed, the estimated cost of which exceeds the sum of twenty-five
hundred dollars shall be made by the said board only upon public letting
founded on sealed bids, except in a case where the board, by resolution,
declares the existence of an emergency or the existence of other
circumstances making competitive bidding impracticable. Notice of the
invitation for such bidding stating the date and place of the receipt
and opening of bids shall be published in the city record in five
successive issues immediately preceding such opening. The board may
reject all such bids and readvertise for new bids if it shall deem it
for the public interest so to do; if not, it shall award the contract to
the lowest responsible bidder unless the board, by unanimous vote, shall
determine that it is for the public interest that a bid other than that
of the lowest responsible bidder shall be accepted.