(4) The Demand of Transportation for High Mentality.—Another noteworthy feature of transportation is that each step of progress demands higher mentality. The most stupid man can carry a load ahnOst as well as the most competent. But a locomotive demands alertness and good judgment; a great steamship needs a highly com petent captain. The automobile does not demand so much skill and judgment as a train or steamship but highly nervous people or those with what the psychologists call a slow reaction time do not make safe drivers. It is said that among colored chauffeurs a relatively slow mental response inherited from generations of tropical environment is sometimes the cause of accidents. Although no exact tests have yet been made, it is said that outside of western Europe and the United States, and perhaps Japan it is not easy to find men whose reactions are quick enough to make them safe aviators.
The management of modern transportation systems demands much higher mental types than does the actual operation. A rather ordinary man can plan the schedule of a stage coach, manage its finances, care for the horses, and do the driving. Only a man of uncommon ability can wisely manage a great railroad with its thousands of employees, its intricate relations with business, its delicate financial adjustments; its keen competition from trolley cars and trucks, and its need of keeping abreast not only of mechanical improvements all over the world, but of the rapidly changing political and business conditions. The necessity for men of unusual capacity not only as engineers, con ductors and repairmen, but especially to plan schedules, meet emer gencies, and plan for the future throws the more responsible positions in large parts of the world into the hands of the European races.
The Great Limitations of Modern Transportation.—In spite of clever methods adapted to almost every type of load, modern trans-• portation, even in progressive countries, does not serve all places equally well. High speed, huge loads, and long runs do not influence peoples' habits and progress nearly so much as does the ability to reach all parts of a region with almost equal ease, but in that respect progress is slow. The trouble is not with the means of locomotion themselves, but with the tracks, roadways and terminals. The train and trolley are limited to the track and can conveniently discharge their loads only at stations. The curves and grades of the track set limits to the size and speed of trains and to the amount that can be accomplished with a given expenditure of power and labor. The great majority of acci dents arise from some defect in the track and not in the actual means of transportation; defective switches, worn rails, broken ties, grade crossings, and the switching of cars from track to track arc the great causes of accidents on trains, while narrow streets, blind intersections, and crowding of vehicles are the chief causes with automobiles. The
steamship can go anywhere over the broad ocean but demands elaborate terminal facilities which can be profitably built only where harbors exist by nature or are constructed by man. Ships are not limited in size by difficulties of construction so much as by shallow channels and inadequate docks. Even at a great port like Liverpool the fact that large ships must wait outside the harbor until the tide rises high enough to provide a deep channel costs hundreds of thousands of dollars each year. Moreover, ships are almost useless unless supplemented by land transportation. The automobile and motor truck travel more freely than the train or the trolley car, but are greatly limited by the roads. Motor roads are often almost as distinct as railroads; if a road falls below a certain standard of smoothness and hardness its motor traffic is limited, the expense for repairs on cars mounts up enormously, and the size of the loads and the' speed of locomotion fall correspondingly. Out West this limitation is locally recognized when people speak of 10-mile, 15-mile or 30-mile roads, depending on how fast an automobile can safely traverse them. It should be noted, however, that more vehicles can pass over a given stretch of crowded road per hour at a slow rate than at high speed. This is because at low speed the vehicles can be close together, not more than 15 feet apart at speeds of 10 or 15 miles per hour. At speeds of 25 or 30 miles about 60 feet is as close as is safe.
At first thought the airplane seems free to travel everywhere, but its freedom is limited to the air. As soon as it tries to land it requires a large area and very special conditions. The difficulty of landing from airplanes is eliminated in part by the helicopter, a horizontal fan which propels the airplane upward, keeps it stationary at one level, or allows it to descend at any desired rate. But the helicopter is extremely expensive and its weight reduces the carrying capacity of the airplane, which at best is slight. Hence, except in war, the chief functions of the airplane thus far are to carry mails and passengers where speed is more important than expense, and perhaps to bring within easy access remote places like tropical plantations where there is not traffic enough to pay for railways or automobile roads. The importance of landing facilities illustrates the fact that the more highly specialized transportation becomes the more it is limited to special tracks or terminals. The old-fashioned horse and wagon are freer in their movements than any modern device, the pack horse is still freer, and the man with a pack on his back is freest of all.