Supply and demand. Oil needs to be refined into gas, we only have so many refineries. The St. Louis Blackout recently took out a refinery and as a result we had higher gas prices due to lack of supply in our area.
We need to develop alternatives to gas, hydrogen is a possibility. Yet we need to find a way to make hydrogen economical, my last look into it cost about $4/gallon to remove hydrogen from water. Now if gas rises to above $4/gallon, we might have to look at hydrogen.
Ethanol is another possbility if only we could spare the food to help make it. Brazil seems to have a good ethanol program, and they started it in the 1970's to ween themselves off of foreign oil. The technology exists for ethanol powered cars and in the midwest we have gas stations that have 85% ethanol.
Don't forget that there is peak oil and peak natural gas, and that the consumption of which leads to more CO2 in the air which might be causing global warming. We need alternatives not to just ween ourselves off of foreign oil, but to reduce CO2 levels.