There are two major factors which retard the general adoption of modern transportation technology and management and the development of an integrated transportation system. One is the existence of national policies, laws and regulations concerning transportation. These laws govern procedures and the economics of individual modes of transportation as well as the competition between modes. Regulation of transportation inevitably affects the characteristics of national and international transportation systems. Regulations governing road transportation, for example, may be so severe and limiting as to discriminate against roads in favour of railways in situations where this would not otherwise happen. Similarly, the development of long-distance slurry pipelines for coal has been blocked by regulations favouring railways. The other potentially retarding factor is of an institutional nature. The handling and transport of minerals has been so fragmented among agents and carriers that in most cases no single operator has full control over the system. From the time the product leaves the mine or mill to its arrival at destination it may well have come under the control of several dozen agents and organizations. This multiplicity creates obstacles to achieving integration within the system.