A large number of different actions can be taken to reduce greenhouse gas emissions. Policy-makers at all levels of government are contemplating and implementing action plans for reducing GHG emissions from transportation and other sectors. But which are most effective and beneficial? Can future emission reduction goals for the United States be achieved cost-effectively with known technologies? This research is a systematic attempt to put technology strategies for GHG emission reductions that have the potential to be enacted over the next couple decades in context for regulators, researchers, and policy-makers.