Source: adapted from R. Carruthers (2003) The Impacts of Motorization and What Can Be Done to Mitigate Them, The World Bank.
As societies are becoming wealthier they undertake a motorization transition where the number of vehicles per capita significantly increases. Looking at major Asian economies, including Japan, China, South Korea and Singapore, at different points in time in from 1960 to 1990 underlines such a transition with a clear exponential relationship between GDP per capita and motorization. After the $2,000 per capita threshold is crossed, the level of motor vehicle ownership, and the expected mobility, increases significantly.