Cars

$7/gallon by 2010?

http://blogs.wsj.com/environmentalcapital/2008/06/26/oil-shock-analyst-predicts-7-gas-mass-exodus-of-us-cars/

"Over the next four years, we are likely to witness the greatest mass exodus of vehicles off America.s highways in history. By 2012, there should be some 10 million fewer vehicles on American roadways than there are today - a decline that dwarfs all previous adjustments including those during the two OPEC oil shocks."

Imagine what it would be like if we actually had a big surplus of road and highway capacity... What would it do to the economy? Would we be able to justify keeping roads in good repair? Roads not kept in good repair would have to be destroyed for safety reasons, and that would carry a cost as well. These certainly are problems that I would have not expected to see in my lifetime.