Private Vehicles for Personal Transportation

In the United States, private personal transportation has become dominated by the automobile, a platform supported on four wheels and propelled by an internal combustion engine (ICE). Some of the reasons why this combination has emerged as the preferred choice are reviewed. Since urban air quality has become an issue, the ICE has kept pace with progressively more stringent exhaust-emissions regulations. Future emissions standards will encourage the use of alternative fuels and battery-electric propulsion. Looking far into the future, the depletion of fossil-fuel resources and/or definitive evidence that greenhouse gases are actually changing the global climate would foster a shift toward nuclear and solar energy. The automobile platform is compatible with such a shift. The ICE and the electric motor remain as potential motive sources, although they would face some difficult challenges.