Those studying the earnings of a railroad company will often find the operating expenses "subdivided under various headings, including the above, which should consist of the following as prescribed by the Interstate Commerce Commission: Fuel, water supply, oil, tallow, waste, and other supplies for locomotives, switchmen, flagmen, watchmen, engine and roundhouse men, telegraph expenses, train service supplies and expenses, station service and supplies, loss and damage, injuries to persons, clearing wrecks, operating marine equipment - if any - advertising, outside agencies, commissions, stock yards and elevators, rent for tracks, yards and terminals, rents of buildings and other property, payments for switching charges, car mileage and hire of equipment greater than receipts therefor, besides superintendence, stationery, printing, and other expenses in connection therewith.

The Wall Street Journal compiled the cost of "conducting transportation" for the fiscal year ending 1906, for fourteen important lines of road. The percentage of this cost to the gross earnings ranged all the way from 29.3% to 42.4%, the average being 36%. Subsequently, this average figure fell to 33%, but it has more recently advanced sharply, especially when the railroads were under government control.