In Buck v. Kuykendall, 267 U.S. 307, 45 S.Ct. 324, 69 L.Ed. 623 (1925), it appears that Buck wished to operate an autostage line as a common carrier for hire for through interstate passengers, over a public highway in the state of Washington. Having complied with the state laws relating to motor vehicles and owners and drivers, and alleging willingness to comply with all applicable regulations concerning common carriers, Buck applied to the state for a prescribed certificate of public convenience and necessity. It was refused on the ground that the territory involved was already being adequately served by the holder of a certificate and that adequate transportation facilities were already being provided by four connecting autostage lines, all of which held such certificates from the state. The state relied upon its statute which prohibited common carriers for hire from using the highways by auto vehicles between fixed termini, or over regular routes, without having first obtained from the state a certificate of public convenience and necessity. Speaking of that statute, the court said, 267 U.S. at page 315, 45 S.Ct. at page 326: " Its primary purpose is not regulation with a view to safety or to conservation of the highways, but the prohibition of competition. It determines, not the manner of use, but the persons by whom the highways may be used. It prohibits such use to some persons, while permitting it to others for the same purpose and in the same manner. Thus, the provision of the Washington statute is a regulation, not of the use of its own highways, but of interstate commerce. Its effect upon such commerce is not merely to burden, but to obstruct it. Such state action is forbidden by the commerce clause. "