Justin Horner points out today that, against all odds, Americans are continuing to drive less and less. Vehicle miles traveled per person plateaued in 2005 and 
then started declining dramatically in 2008. On average, Americans drove about 700 miles per year less in 2012 than they did in 2007.
So will this trend keep up? Horner offers three possibilities:
- The Interrupted Growth Hypothesis: VMT cuts are temporary and increases will resume once the economy picks up (although we know more VMT is not a required, or inevitable, part economic growth);
- The Saturation Hypothesis: car ownership and personal travel budgets have hit their limit, so no more growth is likely;
- The Peak Car Hypothesis: VMT has hit its peak, and history will now see a VMT decline of undetermined length.
In other words, he says, “in the future VMT will either go up, go down, or stay the same.” His guess is that it will continue to go down.
