Abstract
Alternatives to the petroleum-fuelled internal combustion engine have only prospered when concerns about oil availability were high. No single alternative has recommended itself as an obvious solution for all countries, since different countries may not only rank the problems differently, but vary in resources on which to base alternatives. Both resources and environmental priorities may change over time, as, for example, air pollution has replaced oil availability as the major problem. It is thus clear that from a global viewpoint, a wide range of alternatives will need to be investigated, some for immediate or near future application, others as long-term possibilities. (Author/publisher).