Within 10 years rapid technological advances will make the production of electric cars by a major manufacturer a likely possibility. Widespread use of electric cars would drastically reduce the amount of petroleum consumed for urban transportation and also cut automotive air pollution and noise significantly. Under current conditions and trends, however, sales of electric cars are likely to be relatively modest, unless a larger role is deliberately planned for them in order to reap their potential benefits for conservation and environmental quality. This paper is a summary of an investigation of the effects of large-scale use of electric cars on energy, the environment, and the economy.