It is the duty of the Commonwealth to acquire ownership of the railroads which serve as means of general public communication, and to operate them as a single system of transportation. The rights of the States to acquire private railroads shall be transferred to the Commonwealth on its demand. ARTICLE 90 With the taking over of the railroads the Commonwealth also acquires the right of expropriation and the sovereign powers of the States pertaining to railroad affairs. The Supreme Judicial Court decides controversies relating to the extent of these rights. ARTICLE 91 The National Cabinet, with the consent of the National Council, issues the regulations governing the construction, operation and traffic of railroads. With the consent of the National Council it may delegate this authority to the appropriate national minister. ARTICLE 92 The national railroads, irrespective of the incorporation of their budget and accounts in the general budget and accounts of the Commonwealth, shall be administered as an independent economic enterprise which shall defray its own expenses, including interest and the amortization of the railroad debt, and accumulate a railroad reserve fund. The amount of the amortization and of the reserve fund, as well as the purpose to which the reserve fund may be applied, shall be regulated by special law. ARTICLE 93 The National Cabinet with the consent of the National Council establishes advisory councils for the national railroads to co-operate in deliberations concerning railroad service and rates. ARTICLE 94 If the Commonwealth takes over the operation of railroads which serve as means of general public communication in any district, additional railroads to serve as means of general public communication within this district may only be built by the Commonwealth or with its consent. If new construction or the alteration of existing national railroad systems encroaches upon the sphere of authority of the State police, the national railroad administration, before its decision, shall grant a hearing to the State authorities. Where the Commonwealth has not yet taken over the operation of the railroads, it may lay out on its own account by virtue of national law railroads deemed necessary to serve as means of general public communication or for the national defence, even against the opposition of the States, whose territory they will traverse, without, however, impairing the sovereign powers of the States, or it may turn over the construction to another to execute, together with a grant of the right of expropriation if necessary. Each railroad administration must consent to connection with other roads at the expense of the latter. ARTICLE 95 Railroads serving as means of general public communication which are not operated by the Commonwealth are subject to supervision by the Commonwealth.