The same is true of the second form of legal restraint, though in lesser degree. Privilege (such as the deflection of an old line of road by Act of Parliament in order, for instance, to add to the privacy of a park—there were not a few examples of this some generations ago) and the positive legal restraint imposed by existing right of ownership obviously decay pari passu with the development of public powers for driving new roads or broadening existing ones.
The third political factor modifying the trajectory of roads is that of a variety of objects imposed upon communications by varied social uses. As society grows more complex and at the same time wealthier, as new centres of population arise, new forms of travel and new needs to be satisfied by travel, the simple formula of the line of least effort from one point to another suffers increasing modification. You have to consider not only the line of least effort between two terminals, but the due weight to be given to intervening points which do not lie precisely upon that line. As a rule, of course, these new centres exercise their pressure or attraction automatically, and you get a deflection arising not from plan but from gradual necessity. The same thing happens with new needs (as, commerce replacing arms), but it is curious to note how slowly the modification takes place.
We have a good example of this along the south-eastern coast of England. Our ancestors felt no attraction for living in the neighbourhood of the sea. To use the shore as a recreation and the sea air as a remedy is quite a modern idea. The result is that all the old roads connected with the sea as a terminal ran perpendicularly to the coast, uniting a port to the inland country. There is not a main road in England over one hundred years old and leading from the sea which does not start from a port. For good communication connecting up a line of ports laterally there was little need. The result is that to this day, when the south coast has become one long line of great watering-places, many of which are fully developed modern towns on a very large scale, there is still no complete lateral communication. Many of the port bridges, as I point out elsewhere in this essay, are but recently established, many sections of the line are served by imperfect, ill-kept pieces of road; in one or two places it fails altogether (as round Selsey), while in others it is built up (as at Romney Marsh) of patchwork—old lanes running criss-cross to each other haphazard to make the modern line.
CHAPTER VI
THE REACTION OF THE ROAD
The Physical Effects of Roads: The Way in which the Road Compels Communication to follow it: The Formation of Urban Centres and the Urban Habit: The Spread of Ideas by Means of Roads: History Deflected by the Deflection of the Road: The Example of Shrewsbury and Chester: Towns which are Maintained by Roads: The Road in Military History: Results of the Decay of Roads: The Road as a Boundary.
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So far we have considered the origin and development of the Road: that is, the effect of its environment upon the Road. We must turn, in conclusion, to the converse aspect, which may be called “The Reaction of the Road”—that is, the effect of the Road upon its environment. A road once formed immediately begins to affect in some degree the physical circumstances surrounding it, and in a very much greater degree the human relations which it subserves.
The physical effects of the Road are few and may be briefly mentioned. They are all connected with the action of water, save for very rare instances where a particular cutting has precipitated a landslide and one or two other exceptions of the sort. The effect of the made road upon physical circumstances is, in fact, dependent upon the conflict with precipitation in which it is engaged.
It is a general rule in all man’s economic activity that the human effort is at odds with the general tendency of nature. Nature perpetually tends to reassert herself, and to undo what man has done in her despite. The Road is no exception to this rule, and the particular way in which it works you can see by examining typical cases. One of these we shall come across more particularly later on when we discuss the Roman roads of Britain, but it may be worth while to give its general character here.
The Road, finding a small stream, crosses it by a culvert: the Road, finding a ravine with too sharp a gradient on either side, traverses it by an embankment; and then, even if there is no stream at the bottom of the ravine, it leaves a culvert or other drain for the water accumulated after rainfall to soak through. Now, when human effort slackens and the upkeep of a road is no longer sufficient the culvert gets blocked and the Road begins to act as a dam. The lake so formed will in time destroy the obstacle, but before this the Road will change the countryside by the creation of such a lake succeeded by permanent marsh. To-day the phenomenon passes unnoticed because we are still living in a high civilization. But it has affected history strongly in the past. Whenever civilization breaks down you begin to get a series of marshes, with all their accompaniments of fever and the rest growing up along the roads. The greatest examples of the growth of marsh during the Dark Ages were found in Italy, but there are countless examples of the same thing all over the north and west of the Roman Empire, and this spreading of marsh (due also to other causes, such as the abandonment of drains in the fens and the breakdown of locks and sluices on river ways) is largely caused by the special action of the Road.