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