documents the study conducted to compare the technological status and the resultant potential vehicle characteristics for hydrogen-and battery-powered automobiles that could be produced from 1985 to 2000. Both vehicle types potentially afford ope ration independent of petroleum and natural gas fuel supplies with concomitant sharp reductions in vehicle exhaust emissions. The primary objectives of the study were: (1) the assessments of applicable energy storage and propulsion technology for the two basic vehicle types (applied to four-passenger cars), (2) a rigorous comparison of vehicle weight, size, and usefulness versus design range, and (3) an investigation of the relative efficiencies of expending energy from various primary sources to power the subject vehicles. Another important objective, unique to hydrogen-powered vehicles, was the assessment of the technology, logistics, and cost implications of a hydrogen production and delivery capability. Secondary objectives included evaluation of the total costs of vehicle ownership and identification of potential safety problerns. In the interest of limiting study scope, certain restrictions. in propulsion system configuration were adopted. Hydrogen engines were sparkignited, internal combustion engines with appropriate modifications depending upon the energy storage options. Electric vehicle powertrains were direct current systems fed by a single battery type, appropriate to each time period (no dual batteries), without flywheels or other secondary energy storage or propulsion provisions. The information contained in the technology ass es sments was obtained by a review of the literature available up to mid-1977 and by personal contacts with government, university, and industry researchers.