The price of gas now is significantly higher than it was the last time oil prices were this low, and it's because in this country you can charge whatever you want for what you're selling. There are some market forces that help keep retail prices in line with wholesale costs but in our economy the oil companies have lots of power to minimize those price drops whenever wholesale prices drop. For instance, there are only a few refineries in this country, most if not all are owned by the major producers of crude, and as such there's almost no competitive pressure. It costs over a billion dollars to commission a refinery, a pricetag that keeps every single smaller player out of the business.
Here's a place you can compare crude and refined gasoline prices over the years:
http://www.gasbuddy.com/Charts
Click on Gas Price Charts at the top and proceed from there. Don't forget to check the Show Crude Oil Price checkbox at the lower left. You can also search specific areas by entering zip code or other info in the Area boxes.