The Road

by Hilaire Belloc

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In order to understand any matter, especially if we have to understand it for a practical end, we must begin by the theory of the thing: we must begin by thinking out why and how it has come into existence, what its function is, and how best it can fulfil that function. Next we must note its effect, once it is formed, and the results of the fulfilment of its function.

What then, to begin with, is the origin of the Road? Why did this human institution come into existence, and how does it tend to develop? How may it best be designed to fulfil its function?

When we have decided that we can go on to the next point, which is: how does the Road, once formed, react upon its environment; what physical and (much more important) political results flow from its existence?

The answer to the first question, “How did that human institution, the Road, come into existence, and why?” is simple, and will be given in much the same terms by anyone to whom it is addressed. The Road is an instrument to facilitate the movement of man between two points upon the earth’s surface.

If the surface of the earth were uniform in quality and in gradient—that is, if it were of the same stuff everywhere, of the same degree of moisture everywhere, and everywhere level—the Road between any two points would clearly be a straight line (to be accurate, the arc of a great circle) joining those two points. For when we say that the Road exists “in order to facilitate” travel over the surface of the earth from one point to another the word “facilitate” includes, of course, rapidity in progression, and the straight line is the shortest line between any two points.

But the surface of the earth is highly diversified in quality as in gradient. Therefore the trajectory or course of the Road is not in practice, and should not be in theory, a straight line from point to point. That straight line has to be modified if we are to give to the Road an ultimate form such that it shall best serve its end; and when we come to look into the problem we shall see that it is one of very great complexity indeed. That is where the study of the theory even in its most elementary form becomes of such value to the execution in practice. We discover by studying the theory of the Road how many and how varied are the elements of the formula we have to establish. We become prepared in that study for the discovery, in each new particular problem, of any number of novel modifications not present in problems previously attacked.

So true is this that the whole history of progress in road-making is a history of discovering methods for dealing with obstacles either novel in character or only appreciated after lengthy use. Let us begin at the beginning, with the very elements of the affair.

The first element in the theory of the Road may be put thus: To find a formula of minimum expense in energy for communication between two given geographical points under given conditions of travel and carriage.

The diversity of geographical circumstance moulds the formula into its final shape through balanced modifications of the direct line.

The most obvious modifications to a direct trajectory arise from the two primary circumstances of surface and gradient. It is easier to go over one kind of soil than another; easier to go over one kind of surface in summer and another in winter; easier to go over one kind of surface in wet, and another in dry weather; easier to go over one kind of surface with a heavy load and another with a light load; over one with sumpter animals, over another on wheels, and so on.

Again, it is for all kinds of travel easier to go upon the flat than uphill, and this element of gradient is much more complicated than at first it would appear. Thus travel of one kind—travel on foot, for instance—can take a sharp gradient for the sake of a short trajectory more easily than can traffic with burdens; and traffic with burdens carried by animals can take a sharper gradient with advantage than can wheeled traffic; and wheeled traffic differs according to the character of the vehicle in this respect.

Again, a road of diverse use must strike a compromise in its formula between the various needs subserved. If the great bulk of its use is to provide for rapid military advance by marches, you must sacrifice to shortness some of the easier gradients which would be demanded for traffic mainly civilian, yet if of three main users even the least important is incapable of more than a given gradient, your formula can never exceed that gradient, and so forth. So we have even in this simplest and most primary of all analyses of the Road considerable elements of complexity appearing.

As the study progresses an indefinite series of further complexities arises, and one soon reaches that crux in the theory of the Road which has led to so much discussion and which some still call unsolved: whether the formula of the Road is best left to the unconscious or half-conscious action of experiment, which in time should lead to an exact minimum of expense in energy, or whether it is best to arrive at it by a fully conscious, exact, and (as we say to-day) “scientific” examination of all the conditions and a deliberate and immediate conclusion upon them.

Should the road grow or should it be planned? The discussion is not idle. The clash of opinion upon it is at the root of the contrast between national systems, and a right answer will make all the difference between success and failure in our approach to a new road system such as is now upon us.