move ment for good public roads began in western Europe 1 oo years before it started in the United States, a newer country with a sparser population and less accumulated capital. Moreover, the early and wide-spread development of railways in the United States provided facilities for other than short-distance and local transport that were fairly adequate until near the end of the 19th century. Then it became manifest that in the more thickly populated north-eastern States improved county and State roads were necessary. New Jersey acted first, adopting a State highway law in 189o; Massachusetts, New York and some other States soon followed with similar acts. The movement, however, would probably have been much slower than it was, had it not been for the automobile, the use of which rapidly increased after 190o and particularly from 1910 onward, until at the present time there are as many automobiles in the United States as there are families. The demand of the private auto mobile owners throughout the United States for roads that are good throughout the year was strengthened during and after the World War by the operators of motor-buses and of motor trucks, whose use for local passenger and freight transport had increased with great rapidity. The States (aided from 1915 by the Federal Government) have provided the country with a comprehensive system of State and inter-State highways. The
improved highway and the automobile in the United States have brought mechanical transport to each man's door, and the same is true in varying degree in many other countries.
The effect of making mechanical transport universally available has been to create new conditions of living, to increase economic activity, to stimulate wider intellectual interest, to raise standards of living. Possibly the immediate consequences of the sudden change from a relatively static to a highly mobile society may not all be advantageous, but mankind may be expected to adjust itself to the new order of things and to meet successfully the social problems of the automobile era, as it has met the difficulties that have arisen in the past.
No other facility of trans port is receiving so much attention from the public and from technical experts as the aeroplane. The great interest aroused in aeronautics—in the aeroplane and the airship—by the World War has continued unabated, the aim of present efforts (1929) being to establish air transport of passengers and high class package freight, as well as the mails, upon a self-supporting com mercial basis. For a discussion of this subject see TRANSPORT BY