Seems like more and more people -- even conservative economists -- are going on record in support of higher gas taxes.
From an economist's point of view, it's a bit of a no brainer. Like just about any addiction, our gasoline habit carries lots of "externalities" -- costs that fall on everyone rather than just the person who uses the gas. (Think climate change, oil spills, air pollution, security vulnerabilities, international military entanglements, economic risk from oil price shocks, etc.)
If we consumers had to pay those costs every time we filled our tanks, we'd use gas a little more sparingly -- and we'd create fewer externalities as a result. Plus, the taxes could provide a source of revenue to deal with the problems created by energy consumption -- say, a dedicated funding source for ramping up efficiency.
But that begs the question -- just how high should the taxes be?