The Department of Energy released its inaugural quadrennial review last week. The Quadrennial Technology Review concludes that the agency’s top energy investment priority should be making cars more fuel-efficient, eventually through the electrification of vehicles and modernization of the electric grid to support them. The report finds that the domestic transportation sector’s reliance on oil represents one of the most significant economic and national security threats to the country, but the U.S. has underinvested in electric vehicle technologies relative to other technologies.