In most cases the promoter of a bridge project at the outset is possessed of rather inflated ideas as to the possibilities for gain by the materialization of his proposed enterprise, and, in consequence, is inclined to be uneconomical in his layout of structure and of the money expenditure therefor. If he is to make a success of his venture, he should begin without delay an economic study of his problem; and in this he will require the aid of a bridge specialist of wide experience. It will nearly always be found advisable to keep the first cost of structure down to an absolute minimum, but arranging to increase its capacity from time to time as the augmenting business warrants. Generally this is a necessity, because bankers will not furnish money for an extravagantly conceived proposition; but even if the money be available, it would be bad policy to spend any of it unavoidably at the outset, for the reason that the interest on the extra expenditure, up to the time when the facility in question is really needed, might amount to a large sum of money.

The promoter should investigate thoroughly the possibility for traffic of all kinds, keeping his own counsel about what he is doing, in order to protect himself from hold-up by property owners or the malevolent opposition of possible rival promoters. After finishing this investigation of conditions, he should, if possible, determine the kind or kinds of traffic for which the proposed structure should provide and the probable amounts thereof that there will be, both at the outset and for a long series of years, also the net income it will produce.

The preliminary investigations concerning the probable traffic and other sources of revenue should be made with great care and conservatism. One who is optimistic by nature is prone to overestimate, and no promoter is of any account at all unless he is optimistic; hence he should consider very carefully all uncertain matters connected with the revenue estimates, and should endeavor always to err upon the side of safety. Similarly, in computing the annual cost for maintenance, repairs, and other like expenses, he should be careful to omit no items and to figure each item high enough to be beyond criticism.

After his bridge specialist has reported upon the best type of structure to build, the first cost for the minimum amount of construction at the outset, and the subsequent increased costs for enlargements or betterments, the promotor should complete the economic study of the enterprise and

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