In laying out new thoroughfares or treating old ones it must be remembered that with respect to traffic streets the increase in population is constantly making larger demands for width, and that on residence streets the city should not be burdened unnecessarily with the cost of street construction and maintenance. Moreover, there is great economy in the distinct separation of residence streets from traffic streets. Whenever a street railway seizes upon a residence street of ordinary size, that street immediately begins to undergo transformation into a business street; and this change while working its slow way causes depreciation in land values which, save on favorably located corners, amounts to virtual confiscation. With good planning these ruinous transformations become unnecessary, and the purchase of a home then becomes a stable investment and not a gambling hazard. Again, in every country experience has proved that the clear and even remorseless cutting of main lines through the district to be developed, and the division of great blocks into traffic arteries and service streets is the soundest economy, as well as the most effective means of reaching the sought-for end. The second form of traffic interruption, arising from the intersection of lines of movement, is complicated by reason of the fact that here the pedestrian movement, as well as the vehicular movement, must be taken into consideration. There are times when men gather in the streets for patriotic purposes, as on the Fourth of July and Decoration Day; or because of an eager desire to learn the news of great events, like election results. The right of the people to assemble for discussion is fundamental. All these requirements must be met by the creation of open spaces, which appropriately may be adorned by the statues of men of achievement, or may be ornamented with fountains and memorials of various kinds. These spaces for assembly and for embellishment should be arranged so as to allow traffic to flow unvexing and unvexed. Nothing could be more of a makeshift than the arbitrary regulations of the police in many of our cities, where long detours are imposed on the wayfarer and vehicle alike, in order to diminish that congestion which it is the task of the city planner to prevent. Yet in no city in the world has this intricate and perplexing problem been completely solved.