Insubordination means a recorded instance of insubordination within the past three years.

Delinquencies means a record of operating ahead of time, not slowing up at street intersections, etc.

Misses means failure to report.

Set-backs refused means refusal of operator to follow regulations when he has been long delayed in arrival at the end of his run.

Psychological trait G means a group factor: relatively poor performance in the whole battery of tests.

Shorts and overs means turning in more or less money than is shown by the register.

Overtime means a large amount of overtime work as determined by reference to earnings. (Motormen regularly earn from $1,900 to $2,000 a year. They are paid time and a half for overtime. We made this inquiry into overtime work, to see whether fatigue during overtime tended to increase accidents; but we did not find a relation between the two. Even in excessive overtime, indicated by average annual earnings of at least $2,300, we found the same proportion among the high and the low accident groups. Perhaps the explanation is that the men who secure this extra work are older, safer men, as assignment to overtime work is strictly in order of seniority, among the men available.)

first group and 9 per cent of the second had some health defect as determined by the medical examinations.

At least one of these three conditions was present in 77 per cent of the high-accident cases, and in 23 per cent of the low-accident cases. The most interesting finding, however, comes to light when we compare the proportions of high-accident and low-accident men among the thirty-eight motormen who had more than one of these conditions. Thirty-six of them are high-accident men; only two are low. Stated differently, the presence of more than one of these conditions in the same individual occurs in 42 per cent of the high group, but in only 2 per cent of the low group. In other words, within this sample of eighty-six motormen, if a man is defective in health and aptitude, or health and personality, or aptitude and personality, as measured in the way here described, the chances are less than one in twenty that he will be found in the low-accident group.

Findings of this kind emphasize the necessity of individualized treatment of accident proneness, a treatment based on an intelligent diagnosis of behavior patterns exhibited both on and off the job, supplemented when necessary by medical and psychological examinations. Treatment then takes the form of specific instruction, medical attention, encouragement, or discipline, as the individual case may require, together with close supervisory follow-up. Much can be accomplished through the regular channels of supervision, when street inspectors, safety supervisors, and division superintendents all accept their share of responsibility for dealing with the motormen and bus operators in a manner which clearly recognizes the differences between the individuals whose work they oversee - differences in ability and strength, differences in skill and alertness, differences in temperament and health, differences in physique and age, differences in knowledge and training, differences in family circumstances and financial status, differences in worries, anxieties, hopes, and ambitions.

Not only in transportation companies have these basic principles and practical methods of eliminating accidents proved valid. They apply equally to safety work in factories, on aviation fields, and on the public highway.

Understanding and Control of Fatigue. The effects of excessive work - whether traceable to long hours, rapid pace, insufficient rests, muscular overload, nervous tension, inefficient ways of working, lack of training, or other cause - are sometimes primarily physiological, sometimes psychological.

Decreased capacity to do the work in hand is an obvious indicator of changes that work produces. By some investigators, reduced output has been taken as a measure of fatigue. Others have resorted to counts of accidents, errors, or spoiled work as indexes. Such studies have had to reckon with the amazing power of the human being to spurt, to nerve himself to special effort, to pull himself together and perform his task with precision and speed in spite of weariness or exhaustion. The problem is complicated - particularly so since there has been found no close relationship between the objective facts of decreased capacity for work and the subjective feelings of being tired.

Feelings of weariness are often entangled with feelings of boredom, ennui, or distaste for the job. So investigators have sometimes found themselves facing questions about the nature of monotony, or interest in work as related to differences of ability and personality, when their initial problem was that of the nature, causes, or effects of fatigue.

Indeed, the concept of industrial fatigue has proved to be rather ambiguous. Richard M. Page, for example, favors abandoning the term and speaking instead of"energy-cost," a quantity the physiologists are in a way to measure with a good deal of precision. It is of utmost importance to know the energy-cost of different kinds of work performed by different individuals, under different conditions. The feeling-cost, or the price the worker pays in terms of discomfort, pain, weariness, or distress, is every whit as real. It is of immediate concern to both management and worker, even though it cannot be measured as accurately as the amount of oxygen consumed.

To have analyzed this problem of industrial fatigue into separate components and formulated it clearly, is of itself no small accomplishment. To have forged the tools of research for recording and measuring the mental and the bodily phenomena, is another long step toward understanding and control.

Like the effects of practice and of variety of task, the effects of fatigue are of importance partly because of their interrelations with other phenomena. Psychopathologists like Elton Mayo have stressed the disintegrating effects of pessimistic revery, which often seizes a fatigued person occupied with uninteresting work, and have shown that properly systematized rests - especially when the worker has been taught a technique of relaxation - are sometimes the best cure for disgruntlement, radicalism, and excessive labor turnover. It is the needlessly tired man who most easily gets irritated at his boss and develops a grudge or foments a local insurrection. Management consequently studies both the physiology and the psychology of fatigue, with an eye to harmonious relations as well as to health and productivity.