If there is a final approval of the abandonment of the highway by the governing body of the county or by the court, the city or town shall, solely at its own expense, submit to the Commissioner of Highways plans and specifications for a proposed relocation of the highway, containing such information and facts as a location, elevations, and other matters the Commissioner of Highways may require. The Commissioner of Highways shall have the power to change, alter, and amend the plans in order to conform to the views of the Commissioner of Highways as to the location, width, and type of construction of such highway to be built on the new location, provided that the new highway is located such that it will not be flooded by the water to be impounded, and provided further that the Commissioner of Highways may not require a more expensive type or character of highway than the one to be abandoned. The Commissioner of Highways shall approve such plans and specifications either as proposed by the city or town or as amended by the Commissioner of Highways.