Historians sometimes measure the strength and influence of a culture by the rather prosaic method of studying the roads which that culture builds. Portions of the highways of the Roman Empire remain in existence to the present day, with a number of more modern roads following their routes. Construction of the American interstate highway system was a dramatic demonstration of the nation’s industrial power and ambitions in the aftermath of the Second World War. China’s Grand Canal, though a water and not a land road, has united the eastern parts of the country for fourteen centuries and still sees heavy traffic. As engineering achievements, these systems command respect and even admiration. As genuine benefits to humanity, their usefulness is questionable.
A well-maintained and comprehensive highway network increases the interdependency of distant areas. If a resource rare in one district is plentiful in another, and can be easily transported to the locality where it is in demand, its availability encourages residents of the importing area to rely on that external source of supply instead of making the best use possible of their own resources. Furthermore, frequent imports and exports encourage the commodification of resources: the process by which those resources come to be seen primarily as instruments in a business transaction instead of as real objects necessary for human survival. As regions begin to rely more and more on what they can obtain from outside sources, their several local economies merge into a single large one, and in the process they lose their self-sufficiency, placing themselves in danger of economic or literal starvation should anything ever happen to the transport network on which they depend. The resilience of the small, self-contained unit dissolves.
The existence of a highway system, or even a rail system, also stifles the development of new technology for crossing distances. Since the roads are already there, engineers and inventors focus their efforts on making incremental improvements to the vehicles in use on those roads. Such improvements are both simpler and more marketable than alternative lines of inquiry. There is no incentive for them to strike off in new directions or find solutions for personal transport that do not involve roads, as they would be forced to do if they found themselves barred from traveling by natural obstacles and were unable to construct a highway network to solve the problem.
On a personal level, an extensive road network leads to greater social fusion within a large area. Roads make it easier for residents of an area to travel; when they travel, they grow more accustomed to their neighbors. The exchange of ideas that takes place, assuming that it does not cause conflict or violence, eventually increases the intellectual and ideological similarities between the two regions. The result is greater integration of their populations and a threefold decrease in individuality within the society as a whole. First, minority ideas become increasingly outnumbered, and the intellectual shift causes formerly unexceptional ideas to be excluded from mainstream discourse. Second, the combined efforts of the larger population are more effective at actively suppressing dissent. Third, the greater social problems of the combined society encourage the development of a strong and invasive state to resolve them, which further reduces the opportunities for individual expression.
Roads may be a sign of a healthy civilization, or they may be a sign that a civilization has grown too big to be healthy.