During the Middle Ages the art of road making fell into disuse; the people of that time depended on the Roman roads, and built no new ones by lasting methods. The roads and streets of medieval Europe were always in bad condition; sometimes they were impassable. Repairs depended largely upon chance or upon the goodwill of people who owned the adjoining property. But in those days most of the people lived in the country or in small towns, and there were no enormous cities like those of to-day. Great cities depending on outside sources for food would have starved.

Present Day Paving. There was little improvement in the art of road building until a Scotchman named MacAdam came

WELL PAVED STREETS FACILITATE TRANSPORTATION

The same street in a prosperous western town before and after a hard surface roadway was constructed.

forward with some new ideas on the subject, at the beginning of the nineteenth century. MacAdam applied scientific principles to road building. He believed that a road should be built of broken stone, on a well-drained foundation, and with a moderately curved surface, so that water would run off and not gather in pools and make ruts. His name has been perpetuated in the macadam roads that have made motoring possible throughout our land; it is to him that we owe the great and lasting improvement in roads.

Since MacAdam's time, however, many different forms of road construction have been successfully used. Our city streets are paved with brick, with granite, or with wood blocks, set in a concrete or a gravel foundation and cemented with pitch; they are also paved with concrete, or with asphalt, which is the best

paving for general city use. The type of surface that is best depends entirely on the character of the street. On hills an asphalt surface is too smooth and too slippery in rainy or icy weather; granite blocks are better. Wood blocks, because they are less noisy, are excellent for a hospital street. On streets where there is heavy motor or horse-drawn traffic, near freight stations or docks, the granite block is best. But on parkways or boulevards, or main lines of general traffic, asphalt is preferable. Because of its smooth surface asphalt paving is an aid to the Street Cleaning Department; it is easy to sweep.

Roads and Streets Must Be Kept in Good Condition. Streets must be carefully watched for signs of wear, or breaks in the surface, for early repairs mean money saved in the end. One of the worst problems our street departments have to face is that of tearing up the surface to make connections between buildings and water pipes, gas pipes, sewers, or electric wires, which are carried under the street. When the Water Department or the Sewer Department tears up the street to make these connections, it does not always replace a smooth surface. Most cities now have all street work done by an expert street repair force. Contracts for paving new streets are usually let out to private construction companies.

It is the city's duty to keep the streets in such condition that they are safe to use either by day or by night. Authority over streets is usually vested in a Board of Public Works, headed by a director appointed by the chief executive authority of the city. The sidewalks are under the responsibility of the adjoining property owner, who is required to keep his section of the sidewalk in good and safe condition. If he allows the surface to get out of repair, and conditions develop which are dangerous to pedestrians, he is liable to be sued for damages.

At the present time throughout the United States we are in the midst of a "good roads movement." The national, state, and local governments are all interested in promoting better highways. This interest in good roads is mainly due to the increasing use of the automobile and truck. Not only are many

new highways being constructed, but more attention than ever is being paid to the upkeep of roads.

Nearly every state now employs a highway department, usually with a civil engineer in charge, to build roads and to keep them in repair.

A motorist often recognizes a state line by the fact that the smooth road on which he has been comfortably travelling suddenly becomes rough and bumpy. In passing the Federal Aid Road Act, which became a law on July 11, 1916, Congress took a lengthy step toward remedying this situation. Under this law, if a state begins a road-building project it may ask the federal government for help. Then the Bureau of Public Roads of the Department of Agriculture examines the plan. If the project is found to be in harmony with the general scheme of national highways, the government may pay as much as half the cost of the road. Since the passage of this Act, the federal government has appropriated millions of dollars to assist the states in highway construction.

3. PASSENGER TRANSPORTATION IN CITIES

When towns were small, people went from place to place within their limits on foot, on horseback, or in carriages. Horsedrawn stages, and later, horse-drawn street cars on tracks, were familiar sights in our city streets of a hundred years ago. But as communities grew and spread out beyond their earlier limits, a more rapid form of transit became necessary.

The horse-cars were supplanted by the cable cars-slow, jerky affairs they would seem to us in these days. They were pulled along by a cable laid in a conduit between the rails. When the motorman wished to stop, he released the grippers that held his car to the cable; then applied his clumsy handbrakes. New York, Baltimore, Philadelphia, Washington, Chicago, and San Francisco, all had cable cars.

But the cable car system was costly to build, owing to the conduit that had to be constructed under the street to carry the cable; and besides that, the cars were slow. And when the

electric motor car was invented, in a few years it quickly supplanted the cable car. The first successfully operated electric street car line in this country was a thirteen mile system installed in Richmond, Virginia, in 1887, which is still in service. Now every city of consequence has a street railway system. Large cities are abolishing the overhead trolleys, however, in order to get poles and dangerous wires off the streets. The power wires are now laid in conduits between the rails, much the same way as were the old cables.

Even the street cars could not take care of the traffic needs of our ever growing cities. As early as 1831, long before electric

street cars were even

thought of, Col. Stevens of Hoboken, N. J., proposed an elevated street railway system for New York, set along the street curbing on a single line of posts. But his idea was not worked out until nearly forty years later. It was not

before 1878 that New York finally had elevated railroadsfour parallel lines, on which cars were propelled by steam engines. When electric traction was developed, the steam engines were discarded and the lines electrified. Brooklyn, Boston, and Chicago are some of the cities that followed New York's example in installing elevated street car lines.

Now some of our cities have grown beyond the capacity of the elevated lines. Underground railroads have been built under the city streets, and they not only relieve the pressure of traffic on the street surface, but permit operation of trains at a much faster rate of speed than did either the street or elevated systems. The latter is an important factor in drawing people

away from congested districts to live out in the less thickly populated sections. A further advantage of subways is that the streets are not taken up with cumbersome structures, or darkened by overhead tracks and stations, as with the elevated lines. In cities where the business districts are crowded with towering buildings, and the daily business population is enormous, subways have proved indispensable in moving this great population to business in the morning and back home at night. The street and elevated lines literally could not carry the crowds.

Transit Lines a Necessary Public Service. In Chapter XII we saw that a good transit system is one of the essential factors in city growth, for it

develops the outlying sections. If a workman can travel cheaply and quickly from a suburban home to his place of employment, he will often choose to live there because of cheaper rents and greater comforts. But just as soon as the transit companies succeed in raising

fares, or the service becomes slow and poor, the outlying dwellers tend to return to congested districts, with a resulting increase in over-crowding and disease danger. It is easy to see how closely a city's transit system is linked with community welfare and convenience.

Because of this great importance of transit lines to a city's growth and well-being there has come the question as to how these lines should be owned and managed. In the early days of transit development cities were so eager for transportation facili