Nice graph that shows the leveling off of fuel consumption for the foreseable future in the US. How can this possibly happen?

Americans are using less fossil-based fuel than prior to the "Great Recession" and it looks like it is going to continue based on projections from the US Energy Information Agency (USEIA). 

Reasons I can think of off the top of my head:  Persistently high gas prices over the last few years have "nudged" people to trade up (down?) to more fuel efficient vehicles, baby boomers retiring and hence tend to consume less fuel, a trend in teenagers waiting until they are 18 to get drivers licenses AND they tend to drive less relative to teenagers in the past.

I want to include the idleness created by the recession as a reason for a decrease in consumption, which is certainly part of the equation, but that does not explain the projection that consumption will stay level for some time to come.  Surely the economy will recover and fuel consumption  will increase on a per person basis.

How would YOU explain the long(er) term trend in less consumption of various fuels ? (for planes, trains and automobiles et al)

Source: Fiscal Times