27,649 22,653 20,928 18,814 19,582 11,769 9,465 8,233 1,383 6,813 Three-Horse 210 205 173 191 137 123 130 114 74 Passenger Auto under 35 H.P. 56,538 56,183 72,672 11,776 83,026 132,901 167,483 213,440 255,020 283,955 16,247 1,628 1,630 98,702 112,805 171,155 211,003 262,609 309,336 341,468 most optimistic forecasts of a few years ago have fallen far short of developments. The number of cars which can be absorbed by the population of any city depends upon a number of factors. Increase in the population itself is of course the most basic. The financial capacity of the population is another factor, and this is naturally modified by the ability of manufacturers to produce vehicles within a price range capable of attracting all classes, and by operating costs as influenced by fuel, rubber and other maintenance charges. Finally and not least, the number of cars that can be absorbed by the population of any city depends upon the opportunities which the city and the surrounding country offers for safe and convenient operation. Street congestion offers a considerable sales resistance in cities at the present time, discouraging both the purchase and use of motor cars. All of these factors affecting the increase of automobile registration, and therefore density of street traffic in Chicago, are variable and must depend upon future developments. Any estimate of conditions ten or twenty years hence must be in the nature of a guess, more or less accurate as one has been able to anticipate and weigh future conditions. It is possible that the estimates which the Survey has made are considerably below the conditions which will develop. At any rate the future volume which is forecast on this conservative basis is sufficiently startling to demand attention. The present ratio of population to motor cars is 8.9, that is eight and nine-tenths persons for each vehicle. This is on the basis of a present population of 3,048,000 and a motor vehicle registration as revealed by the Wheel Tax Bureau of 341,468.1 This density is far less than that of many other cities. In Los Angeles, for example, the ratio is 2.3, or two and three-tenths persons for each motor car. The decrease in the Chicago ratio has been very rapid during the past fifteen years, however. In 1910 there were 169 persons for each motor vehicle, and in 1920 the ratio had dropped to 22.7. The development in the decade between 1910 and 1920 was due largely to the adoption of the automobile as a new agency, and the rapid increase in registration reflected a sudden growth in popularity. Such an expansion cannot be anticipated in any subsequent period. After a careful analysis of the factors involved the Survey has estimated that the ratio in Chicago will have reached 5 to 1 in 1950, a 1 It is recognized that wheel tax licenses issued fall somewhat short of the number of motor vehicles actually owned and operated in Chicago. NUMBER OF VEHICLES forecast which may be far too conservative. Table 10 indicates the population forecasts together with the number of cars that may be expected in 1930, 1940 and 1950. These data are presented graphically in Fig. 7. A total of 876,000 motor cars in the Chicago urban region in 1950 will mean an increase of 250% over existing conditions. A recent count made by the Survey at the Michigan Avenue Bridge resulted in the checking of 61,434 during a sixteen hour day. The conditions which would exist if 153,585 motor cars should attempt to use this bridge and the streets leading to it is beyond imagination. The full future burden of the Chicago street load is not realized, however, by a mere consideration of urban registrations, for much of the street traffic is at present, and will be in the future, contributed by the metropolitan district. It is estimated that the Chicago Automotive Region (the area within a radius of forty miles) will have a population of 6,408,500 in 1950. If it is assumed that the ratio of ownership of motor cars will be five to one, as for the urban area proper, the number of motor cars in the automotive region will be 1,281,700. Emphasis is placed on the fact that the estimate both as to population and the absorption of motor cars is of the most conservative character. The conclusion is inevitable that the use of the streets of Chicago and the highways leading to it will be at least doubled and possibly trebled within the next twenty-four years. The automobile possesses such utility as a transportation agency, and such convenience to the individual user, that the attractiveness of the city of the future as a place of residence and industry, may depend to no small extent upon the effectiveness with which it handles its growing street problems. FACTORS THAT HAVE INCREASED THE DENSITY OF STREET TRAFFIC IN CHICAGO Having considered in the previous chapter the existing use of the public streets, and the important part which they play in the daily life of the community, it is interesting to turn attention to the principal causes of this great volume of traffic and to some of the conditions which have caused the current congestion of the arteries of travel. Congestion in traffic may be defined as a condition which results in a speed and volume of movement below that desired by contemporary street users. It is a natural corollary of too great density of traffic. Fundamentally the problem of traffic congestion is one of an unbalanced supply and demand. When the demand for street use exceeds the supply, difficulties begin. This is the condition under which the city of Chicago is laboring today. POPULATION AS A FACTOR IN STREET CONGESTION Since the streets must bear a large share of the transportation requirements of the residents of a city the mere gross statistics of residents is in some manner an explanation for street traffic. There are few parallels in the world for the growth of the Chicago Metropolitan area. It is significant that a hundred years ago Boston, New York, and Philadelphia were old cities with substantial populations while Chicago was merely Fort Dearborn, a frontier post with a few hundred settlers. Yet in a century that unpromising frontier settlement has developed into a metropolis with 3,048,000 inhabitants—the second city in the United States, and the fourth city of the world. With this rapid growth there is scarcely any wonder that each year has witnessed a growth in street activities, and that the present one reveals a crowding of the arteries through which the business of the community must be transacted. To a large degree therefore the present street conditions are the result of a mere outgrowth of the original street facilities with which the city has been provided. |