Timing of Transportation Transitions
There is an interesting chart that appears in a new UC Davis report on imagining the future of transportation.[1] The chart comes from a 1998 article in the European Review.[2] The chart illustrates how that prior changes in transportation technology have taken 30 to 70 years to reach peak implementation. The chart is reproduced below.

[1] Ogden, J. & Anderson, L. (Eds.) (2011). Sustainable Transportation Energy Pathways: A Research Summary for Decisionmakers. Davis, CA: UC Davis Institute of Transportation Studies, p. 6 – Available at http://www.steps.ucdavis.edu/STEPS.Book
[2]Ausubel, J, Marchetti, C. & Meyer, P. (1998). Toward Green Mobility: The Evolution of Transport, European Review, Vol. 6, No. 2, 137-156. Available at http://phe.rockefeller.edu/gree_mobility/
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