In America, the basic units have been the ton-mile and the passenger-mile, and these figures are now required to be furnished to the Interstate Commerce Commission and to most of the state commissions as well.
It is useful and necessary, and plays somewhat the same part in economic investigation as ton-mile statistics do in the administration of a railway.
Both the British manager and the American manager, however, are supplied with a considerable number of daily, weekly and monthly reports, varying on different railways, which are not made public. The daily sheets usually include a summarized statement of the performance of every train on the line, covering the amount of business done, the destination of the loads, &c. For a number of years there has been a movement in Great Britain to require the inclusion of ton-mile statistics in the stated returns to the Board of Trade, but most railway managers have objected to the change on the ground that their own confidential information was already adequate for purposes of control, and that ton-mile statistics would require additional clerical force to a costly extent.
