§ 66. Restrictions on the construction of farm and road bridges. A person shall not be entitled to demand a farm bridge across a canal or feeder where the necessity of convenience of such bridge shall have arisen from the division or acquisition of property subsequent to the location of such canal or feeder. A street or road bridge shall not be constructed by the commissioner of transportation over a canal or feeder, except upon such streets or roads as were laid out, worked or used, previously to the construction of the canal or feeder, by which such street or road is obstructed; and when bridges are constructed or reconstructed upon any such streets or roads, the cost to the state shall in no case be more than is required to preserve in a safe and substantial manner the continuity of such streets or roads so as not to unnecessarily impair their usefulness. When a bridge of a more costly nature is desired by the local authorities of a city, town or village within whose corporate limits a bridge is to be built or rebuilt, the commissioner of transportation, on presentation to him by such local authorities of plans and specifications for such bridge and approval thereof by him shall estimate and determine the proportion of the cost, which, in order to preserve the continuity of such streets and roads, the state ought equitably to pay, and file such estimate and determination in his office and a duplicate thereof in the office of the clerk of such city, town or village. If a private road or public highway is laid out by legal authority in such direction as to require the erection of a new bridge over a canal for the accommodation of the road, such bridge shall be so constructed and forever maintained at the expense of the town, village or city in which it shall be situated.