“ Whether the tax shall be state wide or confined to the county or local district wherein the improvement is made, and whether it shall be laid generally on all property or all real property within the taxing unit, or shall be laid only on real property specially benefited, are matters which rest in the discretion of the state, and are not controlled by either the due process or the equal protection clause of the Fourteenth Amendment. ”

“ On the part of the appellant the tax is said to be thus objectionable, because it is imposed to pay for local road improvements and is not apportioned according to benefits, but is laid upon all the property, real and personal, within the district on an ad valorem basis; because the property of the appellant, and particularly its personal property, receives no benefit from the improvements; and because, even if there be some benefit to the appellant's property, the tax laid thereon is disproportionate to the benefit and to the tax laid on other property. ”

“ The Oldham oad district was created, not as a temporary expedient to accomplish a particular road improvement and defray the cost of that work, but as a permanent agency invested with continuing authority to provide and maintain suitable district roads under the supervision of the county board. The state laws provide for accomplishing road improvements and paying therefor in two distinct ways-one through special benefit assessment districts and the other through established local districts authorized to defray the cost by general taxes. ”