American Rural Highways.

by T. R. Agg.

PREFACE

AMERICAN RURAL HIGHWAYS was written for use as a text or reference in courses dealing with rural highways and intended for agricultural engineers, students in agriculture and for short courses and extension courses. The reader is a.s.sumed to have familiarity with drawing and surveying, but the text is adapted primarily for students who do not receive training along the lines of the usual course in Highway or Civil Engineering.

The text is intended to familiarize the student with the relation of highway improvement to national progress, to indicate the various problems of highway administration and to set forth the usual methods of design and construction for rural highways in sufficient detail to establish a clear understanding of the distinguishing characteristics and relative serviceability of each of the common types of roadway surface.

Experience with cla.s.ses made up of students in agriculture or agricultural engineering and with trade school students in road making served as a guide in the selection and arrangement of the material.

Detailed discussion of tests of materials and of the theory of design has to a considerable extent been eliminated as being outside of the scope of the course for which the text is intended.

In the preparation of American Rural Highways reference was had to many books on highway subjects and to current periodical literature.

Wherever direct extracts were made from such source, appropriate acknowledgment appears in the text.

T. R. AGG

AMES, IOWA, AUGUST 18, 1920.

CHAPTER I

THE PURPOSE AND UTILITY OF HIGHWAYS

THE DEVELOPMENT OF HIGHWAY SYSTEMS

=Transportation Problem.=--Public highways, like many other familiar things, are utilized constantly with little thought of how indispensable they are to the conduct of the business of a nation or of the intimate relation they bear to the everyday life of any community. The degree to which a nation or a community perfects its transportation facilities is an index of its industrial progress and public highways const.i.tute an important element in the national transportation system. It is to be expected that the average citizen will think of the public highway only when it affects his own activities and that he will concern himself but little with the broad problem of highway improvement unless it be brought forcibly to his attention through taxation or by publicity connected with the advancement of specific projects.

=National in Scope.=--The improvement and extension of the highway system is of national importance just as is development and extension of railways, and concerted action throughout a nation is a prerequisite to an adequate policy in regard to either. It is inconceivable that any community in a nation can prosper greatly without some benefit accruing to many other parts of the country.

Increased consumption, which always accompanies material prosperity, means increased production somewhere, and people purchase from many varied sources to supply the things that they want. Good transportation facilities contribute greatly to community prosperity and indirectly to national prosperity, and the benefits of highly improved public highways are therefore national in scope. This fact has been recognized in Europe, notably in England, France and Belgium, where the public highways are administered largely as national utilities.

Until recent years, highway improvement in the United States has been subordinated to other more pressing public improvements, but during the World War the inadequacy of the transportation system of the United States became apparent. While such an unprecedented load upon transportation facilities may not recur for many years, it has become apparent that more rapid progress in highway improvement is necessary and in the United States the subject is now likely to receive attention commensurate with its importance.

=Development of Traffic.=--The character and extent of the highway improvement needed in any locality is dependent entirely on the demands of traffic. In spa.r.s.ely settled areas, particularly those that are semi-arid or arid, the amount of traffic on local roads is likely to be small and the unimproved trails or natural roads adequate. But as an area develops either on account of agricultural progress or the establishment of industrial enterprises, the use of the public highways both for business and for pleasure increases and the old trails are gradually improved to meet, at least to some degree, the new demands of traffic. In spa.r.s.ely settled areas, it is possible for the public to accommodate its use of the highways to the physical condition thereof, and business is more or less regulated according to the condition of the roads. This is not always pleasant or economical but is the only possible arrangement. In populous districts, with diversified activities, it becomes imperative to have year-round usable roads in order to transact with reasonable dispatch the regular business of the industries. Anything less will handicap normal community progress.

The advent of the motor driven vehicle in the United States has resulted in a greatly increased use of the public highways of agricultural areas, even of those that are spa.r.s.ely populated, because of the convenience of the motor vehicle both for pa.s.senger and for freight service. Probably in excess of 90 per cent of the tonnage pa.s.sing over the rural highways in the United States is carried by motor vehicles. This cla.s.s of traffic has really just developed and no one can predict what it will be in ten years, yet it has already introduced into the highway problem an element that has revolutionized methods of construction and maintenance.

A different set of traffic conditions exists in those parts of the United States where large areas are devoted primarily to industrial pursuits, the agricultural development being of secondary importance.

Public highways connecting the industrial centers are indispensable adjuncts to the business facilities in such communities and are ordinarily subjected to a very large volume and tonnage of traffic consisting princ.i.p.ally of motor vehicles. The roads first selected for improvement will not be those serving the agricultural interests of the district, but rather those serving the industrial centers.

Inter-city roads of great durability and relatively high cost are necessary for such traffic conditions.

Not infrequently the transportation needs will require a system of both inter-city and rural highways in the same community. There are few areas in the United States where there is no agricultural development. It is apparent therefore that the nature of the highway systems and the administrative organization under which they are built and maintained will differ in various states or areas according to the nature of development of that area agriculturally and industrially. In planning improvements of highway systems, it is recognized that one or more of several groups of traffic may be encountered and that the extent and nature of the improvement must be such as will meet the requirements of all cla.s.ses of traffic, the most important being first provided for, and that of lesser importance as rapidly as finances permit.

KINDS OF TRAFFIC ON PUBLIC HIGHWAYS

=Local or Farm to Market Traffic.=--In strictly agricultural communities the princ.i.p.al use of the highways will pertain to agricultural activities and most of it will be between the farm and the most convenient market center. In the ordinary state, the number of rural families will not average more than six to eight per square mile, but in some districts it may reach twenty families per square mile. The travel from the district around a market center will originate in this rather spa.r.s.ely populated area and converge onto a few main roads leading to market. The outlying or feeder roads will be used by only a few families, but the density of traffic will increase nearer the market centers and consequently the roads nearer town will be much more heavily traveled than the outlying ones. It is apparent therefore that considerable difference may exist in the kind of construction adequate for the various sections of road where farm traffic is the princ.i.p.al consideration. This traffic is made up of horse drawn wagons, transporting farm products and of horse drawn and motor pa.s.senger vehicles, the motor traffic comprising 80 per cent or more of the volume of traffic and a greater per cent of the tonnage.

Motor trucks are now employed to some extent for marketing farm products and, where surfaced highways have been provided, this cla.s.s of traffic is superseding horse drawn traffic.

=Farm to Farm Traffic.=--In the ordinary prosecution of farming operations, a considerable amount of neighborhood travel is inevitable. Farmers help each other with certain kinds of work, exchange commodities such as seed, machinery and farm animals and visit back and forth both for business and pleasure. To accommodate this traffic, it is desirable to provide good neighborhood roads.

Traffic of this sort follows no particular route and can to some extent accommodate itself to the condition of the highways without entailing financial loss, although some discomfort and some inconvenience may result from inadequate highway facilities. This traffic will be partly motor and partly horse drawn, but the proportion of motor driven is large.

=Inter-city Traffic.=--In strictly agricultural districts there is a large amount of travel between towns, both for business and for pleasure. The pleasure travel is mostly in motor vehicles and a considerable part of the business traffic is the same, although horse drawn vehicles are employed to some extent.

In industrial districts there is a large volume of this cla.s.s of traffic consisting of motor pa.s.senger vehicles used for business and for pleasure and of motor freight vehicles used for general business purposes. In addition, there is certain to be a large amount of motor truck freight traffic incident to the particular industrial pursuits of the cities. Where adequate public highways connect industrial centers, there is invariably a very large amount of inter-city traffic, due in part to the needs of industry and in part to concentration of population in industrial centers.

=Inter-County and Inter-State Traffic.=--Automobile touring is a popular means of relaxation, especially on the part of those who live in the cities, although it is by no means confined to them. Traffic of this kind follows the routes where roads are best and pa.s.ses entirely across a county, attracted by some public gathering. Often it is inter-state in character, made up of tourists who are traveling to distant pleasure resorts. Such traffic at present const.i.tutes a relatively small part of the travel on public highways, except on certain favorable routes, but as the wealth of the country increases and good touring roads are numerous, long distance travel will increase and will eventually necessitate the construction of a number of well maintained national highways, located with reference to the convenience of the automobile tourist.

PUBLIC HIGHWAYS AND COMMUNITY LIFE

It is well to recognize the intimate relation public highways bear to the economic progress of a nation. Normal development of all of the diverse activities of a people depends very largely upon the highway policy that is adopted and whether the actual construction of serviceable roads keeps pace with transportation needs.

=Rural Education.=--It has become increasingly apparent during the World War that the demand upon North America for food stuffs is to become more and more insistent as the years pa.s.s. Already the consumption in the United States has approached quite closely to the average production and yet the population is constantly increasing.

The time is not far distant when greater production will be required of the agricultural area in North America in order to meet the home demand for foodstuffs, and many thousands of tons will be needed for export. This need can only be met by agricultural methods that will increase greatly the present yield of the soil. The adoption of better agricultural methods must of necessity be preceded by the technical training of the school children who will be the farmers of the next generation, which can best be accomplished in graded schools with well equipped laboratories and with suitably trained teachers. The problem of providing such schools in rural communities has, in some instances, been solved by consolidating a number of rural school districts and constructing a well equipped building to accommodate the students from an area several miles square. An educational system of this sort can reach its highest usefulness only when adequate public highways facilitate attendance of pupils. The whole trend of rural educational progress is toward a system which is predicated upon a comprehensive highway policy in the district.

=Rural Social Life.=--Closely allied to the rural educational problem is the rural social problem. Motor cars and good roads do a great deal to eliminate the isolation and lack of social opportunity that has characterized rural life in the United States. A high order of citizenship in rural communities is essential to the solution of many problems of rural economics, and such citizens will not live away from the social opportunities of modern life. The rural school house and the rural church may become social centers and local plays, moving picture shows and lectures and entertainments of other kinds made available to those who live in the country. Their enjoyment of these social opportunities will be much more general if the public highways are at all times in a condition to be traveled in comfort. Good homes and good schools on good roads are prerequisites to the solution of many rural problems.

If there is opportunity for those who live in the cities to get some adequate idea of rural life and the conditions under which farming operations are carried on it will correct many misunderstandings of the broad problems of food production and distribution. Reference has frequently been made to the seeming desire on the part of city people to get into the country, and, by facilitating the realization of this desire, a great social service is rendered.

=Good Roads and Commerce.=--That good highways are almost as necessary as are railroads to the commercial development of a nation is recognized but, unlike the railroads, the highways are not operated for direct profit and the responsibility of securing consideration of the demand for improvements is not centralized. Therefore, sentiment for road improvement has been of slow growth, and important projects are often delayed until long after the need for them was manifest.

Movements to secure financial support for highway improvement must go through the slow process of legislative enactment, encountering all of the uncertainties of political action, and the resulting financial plan is likely to be inadequate and often inequitable.

The whole commercial structure of a nation rests upon transportation, and the highways are a part of the transportation system. The highway problem can never receive adequate consideration until public highways are recognized as an indispensable element in the business equipment of a nation.

During the World War all transportation facilities were taxed to the limit, and motor trucks were utilized for long distance freight haulage to an extent not previously considered practicable. As a result, the interest in the motor truck as an addition to the transportation equipment of the nation, has been greatly stimulated.

Many haulage companies have entered the freight transportation field, delivering commodities by truck to distances of a hundred miles or more.

The part the motor truck will play in the future can only be estimated, but it seems clear that the most promising field is for shipments destined to or originating in a city of some size and a warehouse or store not on a railroad spur, and especially when the shipments are less than car load lots. The delays and expense incident to handling small shipments of freight through the terminals of a large city and carting from the unloading station to the warehouse or other destination const.i.tute a considerable item in the cost of transportation.

Mr. Charles Whiting Baker, Consulting Editor of _Engineering News-Record_, states:[1]

[1] Engineering News Record, July 10, 1919.

"It costs today as much to haul a ton of farm produce ten miles to a railway station as it does to haul it a thousand miles over a heavy-traffic trunk-line railway. It often costs more today to transport a ton of merchandise from its arrival in a long train in the freight yard on the outskirts of a great city to its deposit in the warehouse of a merchant four or five miles away than it has cost to haul it over a thousand miles of railway line."

Nevertheless it seems probable that new methods of operating the motor truck transport, and possibly new types of trucks or trucks and trailers will be developed so that freight traffic over many roads will be of considerable tonnage and an established part of the transportation system of the nation. In the article above referred to are given the following data relative to the cost of hauling on improved roads by motor truck and these cost estimates are based on the best information available at this time. They should be considered as approximate only, but serve to indicate the limitations of the truck as a compet.i.tor of the steam railway.

TABLE 1

TRUCK OPERATION COSTS, FROM REPORTS BY SIX MOTOR TRUCK OPERATORS, DIRECT CHARGES PER DAY

+---------+-------+-------+-------+-------+-------+-------+----------- | A | B | C | D | E | F | Average | | | | | | | Total +---------+-------+-------+-------+-------+-------+-------+----------- Driver | $5.00 | $5.20 | $5.00 | $5.00 | $5.17 | $5.50 | $5.13 Tires | 3.00 | 3.75 | 2.00 | 2.00 | 2.00 | 3.00 | 2.68 Oil, etc. | .30 | ... | .30 | .50 | .25 | .25 | .35 Gasoline | 3.00 | 4.00 | 3.50 | 4.65 | 2.08 | 3.75 | 3.50 | | | | | | | ------ | | | | | | | $11.66 +---------+-------+-------+-------+-------+-------+-------+-----------