Who doesn’t love a great infographic? We were looking through a recent work titled The Geography Of Transport Systems (New York: Routledge, 2009 ed.) by Jean-Paul Rodrigue, Claude Comtois and Brian Slack, and came across this thought-provoking chart (p. 65) depicting the growth of transportation systems in the United States from the 19th to 21st centuries. (Click image to enlarge)

A section discussing past trends and uncertain futures asks “Where are the flying cars? Where are the supersonic passenger jets?” and goes on to demonstrate that transportation modes experience related life-cycles consisting of peak years and paradigm shifts:

The growth of transport systems, as the case of the United States exemplifies, went through a series of waves of introduction, growth, maturity and decline as massive investments in infrastructures and development of the system took place.

Each time there is a substitution from one mode to another, moving to a higher level of speed (and sometimes efficiency). A paradigm shift represents an event that marks the prominence of transport systems, often characterized by the completion of a significant infrastructure project which starts to impact economic and spatial systems. A peak year is when the system is about to reach maturity and experience a slowdown in its growth.

As you examine the chart here, it shows that the U.S. canal system took off around 1825 upon completion of the Erie Canal, and hit its peak in 1836 as the rail system was beginning to be built. The authors have noted that rail was a more flexible and efficient inland transport system, thus contributing to its advent as a preferred transportation mode.

But by the 1850s, rail traffic was already growing at such a fast rate that it surpassed canal traffic as a primary transportation mode with the completion of the transcontinental railway in 1869. By the late 19th century, most of the U.S was serviced by rail, which grew steadily until it peaked in 1891.

Rail was replaced as a preferred or most efficient means of transportation due to the advent of a national road system, especially after the introduction of the Ford Model T, marking another paradigm shift toward roads in 1913. That “tipping point” year is delineated as the paradigm shift. Roads ruled until their peak in 1946, when the advent of air travel continued the pattern, reaching a paradigm shift in 1969 until its own peak in 2001.

So many new technologies may play a part in future transportation modes, it is difficult to predict what will come next (such as Maglev, which the chart puts forth as a mode of future growth).

The authors duly note that:

One of the pitfalls in discussing future trends is looking at the future as an extrapolation of the past. It is assumed that the future will involve a technology that already exists, but simply operating on an extended scale beyond what is currently possible. The parameters of such an extrapolation commonly involve a greater speed, mass availability, a higher capacity and/or better accessibility, all of which imply similar or lower cost.

In other words, it is safe to say that some technological developments outside of transportation could inform the next great paradigm shift, such as automated processes and alternatives fuels.

Although people-movers and monorails may be past their prime, we may one day see those flying cars after all.