Not All Transportation Fuels Can be Used to Fuel Every Vehicle Type

• Previous studies do not account for recent developments in natural gas (e.g. methane leakage) extractions and current vehicle technologies. • Findings from previous studies on life cycle GHG emissions of natural gas developments and heavy-duty vehicles are mixed and contradictory. • Research Questions • Which natural gas pathways or which vehicle segments provide GHG emissions reductions compared to petroleum fuels? • How sensitive are the results to methane leakage rates and other factors? A Transition to Natural Gas Pathways