Answers showed that in Group I cities 61 percent of the stores reported interference, 53.6 percent in Group II cities, 46.5 percent in Group III cities and 22.3 percent in Group IV cities. In Group I and Group II cities answers from subcenter shopping districts were tabulated separately, and showed 32.9 percent and 16.6 percent interference respectively. On the basis of these answers the division concluded, "It is believed that these percentages confirm the supposition that a large proportion of retail business is being interfered with by congested vehicular traffic. Attention is called to the fact that interference was reported not only from the central district stores, but that subcenter establishments also reported a considerable loss.

In addition to determining the scope of interference the study also attempted to arrive at a conclusion as to the seriousness of interference to individual stores. The data collected were not sufficiently broad to warrant confident conclusions, but they indicate the attitude of the merchants' and something of the relation between retail business and congestion. Merchants in cities in Groups I and II who reported percentages of interference made estimates ranging from 5 to 50 percent. Stores representing seven selected lines of merchandise reported an appreciable interference. As a conclusion on the degree of interference the report states, "Where congestion occurs and interference results, volume of business has been brought down from 1 percent to 20 percent below that which would have been transacted with the automobile as a 'business-bringer' minus the factor of congestion."

DIRECT COSTS OF STREET CONGESTION

Having considered the relation of street traffic to the economic structure of the city, attention is now turned to some of the immediate burdens created by street congestion. Since every active person among the three million and more inhabitants of the city must use the public ways to carry on his or her business or social activities, delays and their costs are of interest to every citizen.

It is impossible to place a value upon the sum total delay occasioned by present street conditions. Various Various attempts of this kind have been made in the past, but at best they can be based only upon the most questionable of assumptions. Perhaps the best that can be said for the general inconvenience suffered by the public is that it

makes the city a less desirable place in which to live, and that it involves an expenditure of energy, and time, which though having no immediate monetary value, the public would be willing to avoid by the payment of many millions of dollars a year. While much of the time spent in street travel is not a part of the gainful occupation time of the general public, the average individual would be willing, to pay a few cents extra per day if the time spent between his home and his work could be materially reduced.

There are certain factors in street use, however, which can be more specifically evaluated. The principal agencies which carry persons and commodities over the streets operate at ascertainable costs. Obviously any delay which these agencies suffer because of congestion adds to their cost of operation, which cost in turn must be shifted to the users of these services. In the case of passenger common carriers, such as street cars, motor busses, and taxicabs, additional costs are translated into additional charges borne by the users. In the case of agencies hauling commodities, the added costs are passed on as increased prices of materials, and these are reflected in higher commodity prices to the ultimate consumers. If delay adds to cost of street transportation, it is of course true as a corollary that any relief in existing delay will reduce the costs of operation and hence the cost of the service to the users.

Street transport plays a very substantial part in the cost of living in every large city. Each individual is of course aware of the amount which he pays for his personal transportation. The indirect costs of living which are to be found in commodity prices resulting from cartage of materials is less well known, and, therefore, its burden less realized.

In order to illustrate the part played by urban cartage, three staple commodities have been selected without any attempt to choose those that would give the most startling comparisons.

Oranges from California to Chicago take a freight rate of $1.55 per hundred pounds. Oranges from Florida take a freight rate ranging around $1.10 per hundred pounds. The cost of drayage to retail grocers and consumer is approximately nine cents per hundred pounds.

The principal potato movement to the Chicago market is from Moorhead, Minnesota, the freight rate to Chicago being 412 cents per hundred pounds. The rate from Waupaca, Wisconsin, another im

portant shipping point is 2012 cents. Drayage costs in the city average about 10 cents per hundred pounds, being equal to from 25 to 50 percent of the freight rate.

The principal coal supply for Chicago is from Illinois fields, embracing six shipping points, which with freight rates to Chicago are indicated below:

The drayage costs figure at approximately 90 cents per ton, which it will be noted is a substantial percentage of the freight costs.

It has been impossible for the Survey to obtain accurate figures on existing traffic delays and to estimate from these, the burden which is thrown on the public. It is well known, however, that a considerable proportion of the operating time of street agencies is wasted because of congestion. It is believed that a considerable proportion of the present loss is preventable. Experience with certain types of regulation in Chicago and in other cities indicates that substantial savings are possible.

The figures in Table 18, which by no means should be taken as exact, give some impression of the amount of money involved in street traffic operations and the saving that would result from even moder

TABLE No. 18

DAILY SAVINGS ESTIMATED THROUGH REDUCTIONS OF DELAYS TO VARIOUS TYPES OF STREET TRAFFIC AGENCIES

NOTE: Costs per unit hours have been taken to some extent from Report to the Commissioner of Public Works on the Chicago River Bridge Survey, by Griffenhagen and Associates, Ltd., Part III.

ate reductions in delays. A saving equivalent to ten per cent of the total operating time of the vehicles noted would mean $75,820 per day or $27,295,200 per year, an amount which would substantially affect the cost of living in the city.

In some cases attempts have been made in Chicago to estimate accurately the losses involved in various types of traffic delay. The most notable of these is the study made for the Commission of Public Works and known as the Chicago River Bridge Survey. After an analysis of existing traffic and the delays caused by bridge openings, the report concluded that under present conditions the public must carry a burden of $216,940 per year. This delay cost is made up out of $31,646 for passenger automobiles and taxicabs, $38,095 for commercial vehicles, $14,812 for street cars, elevated cars and busses, and $132,386 for passengers and pedestrians.

COSTS OF ACCIDENTS

The loss of earning power resulting from injuries and the destruction of property by accident are just as certain a community loss as waste or the destruction of gainful time or capital in any other form. The burden carried by the city in the form of suffering, grief, and poverty because of street accidents is great, but these factors are humanitarian rather than financial, and it is impossible to attempt to estimate their monetary weight. The annual loss to Chicago through personal injuries and property destruction resulting from street accidents is estimated to be $17,000,000."

The foregoing discussion of the economic effects of street traffic congestion, vague and general as it must be through lack of accurate data, will nevertheless reveal the fact that under the most conservative estimates, conditions on the streets do have a profound effect upon the economic structure of the city. Freedom or congestion of street traffic will result in an economic solidarity or it will result in an uneconomic decentralization, respectively. The city will be able to conduct its local

1 Prepared by Griffenhagen & Associates, Ltd., and submitted to the Mayor and the Council, June 15, 1925.

2 For the factors composing this total see Chapter VI.

business effectively or it will be forced to function under a substantial handicap.

Year by year there is being carried on in Chicago as the density of the city increases an experiment in municipal functioning rarely paralleled in any other place in the world. Chicago owes its prosperity to industrial and commercial activity solely. The problem which confronts the city in a very definite manner is how large can a city of its character become before its mere bulk and complexity begin to offset the economic advantages of large scale activity. In other words, how soon, will the law of decreasing returns manifest itself, in such a manner as to impair the commercial efficiency which the city now possesses, and throw the advantage to smaller rivals in the middle west. This time will be determined to no small degree by the ingenuity and energy which civic leaders possess in reducing to a minimum those factors, street traffic congestion among them, which serve to add to the burdens of the community.