PREDICTIONS – 10 Years Later - Santa Fe Institute

7. COMPETITION IS THE CREATOR AND THE REGULATOR
an overall network. The growth of the total length of this network over
the past two hundred years has followed an S-curve and has reached
more than 80 percent of its final size, as Grubler shows. 11 Each separate
infrastructure can be expressed as a fraction of this total. Each system
enters, grows, reaches a phase of maturity when it commands a dominant
share (more than 80 percent) of the total “market,” and then
declines. Curiously, the phase of maturity is reached long before the end
of construction. The total railway track grew by a factor of ten between
the time railways enjoyed maximum share in the competitive picture
and the time when construction finally ceased.
In the generalized substitution model the succession of the different
transportation infrastructures outlines a typical mountainous landscape
(Appendix C, Figure 7.1). From the beginning of the 19th century, the
share of canals declined along a straight line in favor of railways, whose
share reached a peak around 1880, commanding more than 80 percent
of all transport mileage, with the remainder split equally between canals
and roads. As the road mileage increased rapidly the share of railways
declined, despite continuous growth in the length of railway track. The
early twentieth century witnessed a one-to-one substitution between
transportation by rail and transportation by road. The growth in relative
importance of paved roads reached saturation by the 1960s when its
share reached more than 80 percent, and railways split the remainder
with airways. Finally, airways “phased in,” claiming a significant share
by the second half of the twentieth century, forcing paved roads to enter
a relative decline.
In the case of air transport the “length” is defined as the total route
mileage operated by the airways. This estimate, based on an analogy to
the physical lengths of the other infrastructures, is rather crude. Air
routes are opened and closed in response to market demand, while such
a response usually represented a major undertaking for the builders of
canals, railway tracks, and paved roads. Still, the fact that the data agree
well with the substitution-model description comes as a confirmation of
our hypotheses.
The successive declines observed are not due to the physical destruction
of the infrastructure’s mileage. “Phasing out” is relative and
mainly due to the fact that each new means of transportation increased
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