Which states are most vulnerable to gas price spikes?

The Natural Resources Defense Council released a report yesterday ranking the states that are most vulnerable to gasoline price spikes. The report is meant to determine which states are making the greatest effort to lessen their dependence on foreign oil.

In 2009, drivers spent less on gas than in recent years:

Drivers in 2009 spent a markedly lower percentage of their income on gasoline than they did in 2008, and drivers in all but five states actually spent a lower percentage than they did in 2006. This is largely due to the fact that gas prices went down, dropping from the record high prices we saw in 2008. This is a notable change in the trend of the past few years, which saw increasing vulnerability. But with gas prices once again beginning to rise, vulnerable states will be even more at risk.