In the hybrid electric vehicle scenario, we assume that gasoline-powered HEVs continue to capture increasing fractions of new cars sold. No other vehicles are sold in this scenario, so we can determine the impact if we stop at hybrids, and do not add any other alternative vehicle.

The fraction of new hybrid cars sold in the US increases from approximately 2% in 2006 up to 98% by the end of the century. Note that the number of HEVs on the road will lag these new car sales numbers by 15 to 18 years as older cars are retired.

[Gasoline PHEV Scenario] [Biofuel PHEV Scenario] [FCEV Scenario]