Source: adapted from E.J. Taaffe, H.L. Gauthier and M.E. O'Kelly
(1995) Geography of Transportation, Second Edition, Upper Saddle River,
NJ: Prentice Hall, p. 223.
Chicago's beta Values for Air Transportation, 1949-1989
Technological innovations had impacts on the friction of distance,
which is reflected in the reduction of the beta exponent of spatial
interaction models. In this example, the emergence of jet planes had
significant impacts on the reduction of the beta exponent in the 1960s.
Improved speed and capacities made air transportation more affordable
and air travel (interactions) increased substantially.