Rates are usually based on distance traveled, on the apparent hypotheses that each additional mile of distance adds its proportional amount not only to the service rendered but also to the expense of rendering it. Neither hypothesis is true. The value of the service of transporting a passenger or a ton of freight from A to B is a more or less uncertain . gross amount, depending on the necessities of the case and independent of the exact distance. Except for that very small part of passenger traffic which is undertaken for the mere pleasure of traveling, the general object to be attained in either passenger or freight traffic is the transportation from A to B, however it is attained. A mile greater distance does not improve the service rendered; in fact it consumes valuable time of the passengers and delays and perhaps deteriorates the freight. From the standpoint of service rendered, the railroad which adopts a more costly construction, and thereby saves a mile or more in the route between two places, is thereby fairly entitled to additional compensation rather than have it cut down, as it would be by a strict mileage-rate. The actual value to a passenger of being transported from New York to Philadelphia depends on his individual requirements, which may vary from a mere whim to the most imperative necessity. In one case the money value approaches zero; at the other extreme, money could hardly measure the loss if the trip were impossible. If the passenger charge between New York and Philadelphia were raised to $5, $10, or even $20, there would still be some passengers who would pay it and go, because to them it would be worth $5, $10, or $20, or even more. Therefore, when they pay $2.50 they are not necessarily paying what the service is worth to them. The service rendered cannot therefore be made a measure of the charge, nor is the service rendered proportional to the miles of distance.

The idea that the cost of transportation is proportional to the distance is much more prevalent and is in some respects more justifiable but it is still far from true. This is especially true of passenger service. The extra cost of transporting a single passenger is but little more than the cost of printing his ticket. Once aboard the train, it makes but little difference to the railroad whether he travels one mile or a hundred. Of course there are certain very large expenses due to the passenger traffic which must be paid for by a tariff which is rightfully demanded, but such expenses have but little relation to the cost of an additional mile or so of distance inserted between stations. The same is true to a slightly less degree of the freight traffic. As shown later, the items of expense in the total cost of a train-mile, which are directly affected by a small increase in distance, are but a small proportion of the total cost.

136. The Conditions Other Than Distance That Affect The Cost; Reasons Why Rates Are Usually Based On Distance

Curvature and minor grades have a considerable influence on the cost of transportation, as will be shown in detail in the succeeding chapters, but they are never considered in making rates. Ruling grades have a very large influence on the cost, but they are likewise disregarded in making rates. An accurate measure of the effect of these elements is difficult and complicated, and would not be appreciated by the general public. Mere distance is easily calculated; and the railroads therefore adopt a tariff which pays expenses and profits, even though the charges are not in accordance with the expenses or the service rendered.

An addition to the length of the line may (and generally does) involve curvature and grade as well as added distance. In this chapter is considered merely the effect of the added distance. The effect of grade and curvature must be considered separately, according to the methods outlined in succeeding chapters. The additional length considered is likewise assumed not to affect the business done nor the number of stations, but that it is a mere addition to length of track.

137. Variable Effect On Expenses Of Extent Of Change In Distance

It will be developed later that the actual added expense of increasing the length of the line will depend very largely on the amount of that increase. An engineer frequently has occasion to make a slight change in the alinement which may make a difference in the length of the line at that place of a very few feet. It is demonstrable that certain items in the expense of operation will be absolutely unaffected by such a change, while other expenses will be increased nearly, if not quite, in their full proportion. On the other hand, if the change of line amounts to several miles, a very much larger proportion of the expenses will be increased in their full proportion. If the question of substituting an entirely different location on a division of approximately 100 miles was being considered, then, so far as distance itself was concerned (ignoring for the moment the question of curvature, grades, etc., which must be considered separately), the expenses of transporting freight over either of those two lines would be more nearly proportional to the exact mileage. This phase of the question will be considered in detail later on.