All streets, alleys, other public ways and railroad rights of way, if not otherwise specifically designated, shall be deemed to be in the same use district as the property immediately abutting upon such streets, alleys, other public ways and railroad rights of way. Where the centerline of a street, alley, other public way or railroad right of way serves as a district boundary, the zoning of such areas, unless otherwise specifically designated, shall be deemed to be the same as that of the abutting property up to such centerline.