The items of maintenance of way are more nearly affected in proportion to the distance than any other group of items. In fact it will be easier to note the exceptions from a full 100% addition for all increases of distance. The cost of track labor, which is such a large percentage of the total cost of Item 6 (see Table IX in Chapter VI), and also the cost of all track material, will vary almost exactly in accordance with the distance. If the track-labor was so perfectly organized that there were no more laborers than could precisely accomplish the necessary work, working full time, then any additional labor would necessarily require a greater expenditure for laborers. Although a division of a road is divided into sections of such a length that a gang of say six or seven men will be employed as steadily as possible in maintaining the track in proper condition, the addition of a few feet of track would not probably have the effect of increasing the number of sections, nor would it even require the addition of another man to the track-gang. It might require a little harder work in maintaining a section, it might even mean a slight lowering in the standard of work done in order that the whole section should be covered. The fact remains that the cost of track-labor will not inevitably and necessarily be increased in a strict proportion to the increase in distance. On the other hand, it would not be wise to rely on any definite reduction or discount from the full 100% of work required, since to do so implies that, with the lessened distance there would be some loafing on the part of the track-gang, or that with the added distance the men would be overworked or would be compelled to slight their work. The items, renewals of rails and renewals of ties, should certainly be considered as changing in direct proportion to the distance. Therefore it is only safe to allow the full 100% addition for Items 1 to 7.
The repairs and renewals of tunnels, bridges, culverts, fences, road crossings, signs, cattle-guards, buildings and fixtures, docks and wharves, etc. (Items 8 to 17), may perhaps be considered in the same way, although there are some of these items on which the effect is more doubtful. If a proposed change in line does not involve any difference in the number of streams crossed, then the number of the bridges and culverts will not be altered, and although the size may be altered, the effect of the change on the cost for repairs will probably be too insignificant for notice. For small changes of distance it may very readily happen that no bridge or culvert is involved. For great changes of distance, especially those which would involve an entire change of route for a distance of many miles, it might be proper to consider Item 9 to be affected fully 100 %. Although Items 9 and 10 are small, averaging about 1.8%, the error involved in these items by considering that the change amounts to 100% for great distances and zero for small distances will be almost inappreciable. For Items 11 to 13 the full 100% will be allowed for all changes of distance, for the same reason as previously given for repairs of roadway. Item 16 will usually be absolutely unaffected by a small change in distance, since it does not usually involve any buildings or fixtures, Larger changes of distance will probably require some change in the number of minor buildings required, but such buildings will be the more insignificant buildings, and we are therefore making ample allowance, if, under ordinary conditions, we estimate that 20% of the average cost of all buildings (which include terminals, etc.) is allowed for this item. Under ordinary conditions Item 17 will be absolutely unaffected by any changes in aline-ment which the engineer may make. An addition to distance will not usually affect the telegraph system, except as it adds to the number of telegraph-poles and to the amount of wiring and pole fixtures. Therefore any addition to distance will not add more than 50% to the average cost of Item 14. Items 18 to 21 are insignificant in amount, and can hardly be said to be affected by any small difference in distance which would ordinarily be measured in feet. Larger differences, which are meas-ured in miles and which may involve, for instance, all the blank forms required for the reports of an additional section-gang, additional pay-rolls, etc., will be increased to practically their full proportion. Therefore there is but little error involved in allowing 100% on these items for changes of distance measured in miles.