Figure 2:
Railways tracks and paved roads in kilometres: (a) El Salvador and Malawi; (b) Brazil and India. Source: World Bank, Infrastructure for Development, World Development Report 1994 (Oxford and New York: Oxford University Press, 1994), 140–145; CIA World Factbook, https://www.cia.gov/library/publications/the-world-factbook/fields/2085.html#182. International Road Federation, World Road Statistics 2007, Data 2000–2005, Geneva 2007.