§ 51. Maintenance and repair of highway crossings on abandoned canal lands. The maintenance and repair of highways on any parcel of such canal lands which have heretofore been abandoned pursuant to law and which have been converted into crossings at grade or which may hereafter be abandoned pursuant to law and so converted shall be the responsibility of the municipality within which such parcel of abandoned canal lands is situated. The provisions of this subdivision shall not supersede any of the provisions of the highway law.