N.Y. High. Law § 187
An application to lay out a highway upon the line between two or more towns, or wholly in one town but adjacent to another town, shall be made to the town superintendents of each town, who shall act together in the matter; and, upon laying out any such highway, the expense of opening, working and keeping the same in repair shall be borne equally by such towns. The town superintendents shall cause a map and survey of the highway to be recorded in the office of the town clerk in each of the respective towns. If such highway be upon a line between one or more towns and a city or incorporated village, or wholly in one town, village or city but adjacent to another town, village or city, such application shall also be made to the officers of such city or village having the powers of the town superintendents and such officers may agree with the town superintendents of such towns as to division of such expense. Whenever such officers shall disagree, the question shall be submitted to the county superintendent or superintendents representing the county or counties in which such highway is located and their decision shall be final when approved by the department of transportation. All highways heretofore laid out upon the line between any two towns or between a town and a city or an incorporated village, or wholly in one town, village or city but adjacent to another town, village or city, shall be divided and allotted or redivided and reallotted, recorded and kept in repair in the manner above directed; and all bridges upon such highways shall be built and maintained jointly by the towns whether wholly located within one of them or otherwise. Such highway or part of such highway may be improved by paving, repaving, macadamizing or remacadamizing upon agreement between the town board of such towns, the village trustees of such village, or the common council, council or other governing body of such city, and the cost of such improvement be paid by each city, town or village involved, in the proportion recited in such agreement. The officers of such city, town or village may proceed with the ordering, construction and pavement of such improvement in the manner prescribed by law where a highway is situated wholly within such city, town or village except as is otherwise provided in this section. Where action by the officers of such city, town or village is required by law to be upon a petition of the owners of lands lying in and along the highway to be so improved, such petition will be sufficient if made only by the specified number of such land owners in and along the side of the highway within such city, town or village, without requiring the signatures of the owners of the land in and along the side of such highway not within such city, town or village. Plans and specifications for such improvement shall be approved by the officers of each such city, town or village involved and may provide for the maintenance of such improvement for a period not exceeding ten years after its completion. The contract for the construction of such improvement will be let subject to the approval of the officers of each such city, town or village to the lowest responsible bidder upon bids received after notice of advertisement as may be required by law in one or the other of such city, town or village, and bids may be received by the officer and at the place in one of such cities, towns or villages agreed upon by the officers of each such city, town or village involved. The construction of such improvement may be under the supervision of the officers of each of such cities, towns or villages, or under the supervision of such person or officer as may be agreed upon by the officers of such city, town or village. Where the cost of such improvement is required to be met by local assessment upon the lands benefited, each such city, town or village shall cause the portion of the cost of such improvement to be borne by each such city, town or village, to be levied and assessed upon the lands within such city, town or village along the highway or part of the highway so improved in the same manner and with the like effect as is required by law for the assessment of the cost in part or whole of similar improvements upon a highway wholly within such city, town or village. After the completion of any such improvement such improvement shall be maintained equally by the city, town or village in which or along which such highway is laid out in the manner provided by the agreement referred to in this section to be entered into between the officers of such city, town or village. Each such city, town or village may construct and maintain, or provide for the construction and maintenance, in such highway of sidewalks, sewers, water lines, gas lines and other public service facilities to accommodate the lands adjacent to such highway and situated within such city, town or village in the manner provided for the construction and maintenance of sidewalks, sewers, water lines, gas lines and other public service facilities within a highway wholly within such city, town or village.
Where such highway is partly within a city, and where it has been designated by law as a state highway, the state, through the department having supervision over state highways, may enter into an agreement with such city allotting to the city the part of such highway to be paved, macadamized, or otherwise improved by the city, and the part of such highway to be paved, macadamized or otherwise improved by the state, in which case the city will improve the part of the highway so allotted to it in the manner in which it improves a highway situate wholly within the city, and the state will improve the portion of such highway allotted to it as a part of the state highway. Where the cost of such improvement is required by law within said city to be defrayed in part or in whole by local assessment, all of the lands within said city along the lines of the highway so divided, and extending one hundred feet at right angles therefrom, will be deemed to be benefited by the construction of such improvement by such city and will be subject to be assessed to defray the expense thereof the same as if such lands abutted upon the part of the highway so improved by such city. Where any such highway is partly within a city, and is on the county road system of town highways proposed to be constructed pursuant to the provisions of article six of this chapter, the board of supervisors of the county, with the approval of the commissioner of transportation, may enter into an agreement with such city allotting to the city the part of such highway to be paved, macadamized, or otherwise improved by the city, and allotting to the county the part of such highway to be constructed, paved, macadamized, or otherwise improved by the county pursuant to such article, in which case the part allotted to the city shall be improved and maintained by the city in the same manner in which it improves and maintains a street situate wholly within the city, and the county shall improve and maintain the portion of such highway allotted to it as a part of the county road system of the county. The county superintendent of highways of the county, upon the execution of such agreement, shall prepare a map showing the part of such highway within the city and town allotted to the county as a part of the county road system. This map must be approved by the board of supervisors of the county and by the commissioner of transportation before it becomes effective, and when so approved shall be filed in the office of the department of transportation, county clerk and county superintendent. When the cost of such improvement within the city is required by law to be defrayed in part or in whole by local assessment, all of the lands within such city along the line of the highway so divided, and extending one hundred feet at right angles therefrom, will be deemed to be benefited by the construction of such improvement by the city and will be subject to be assessed to defray the expense thereof within the city the same as if such lands abutted upon the part of the highway so improved by the city.
N.Y. High. Law § 187