Reason No. 3: The price of oil has been falling
One of the primary reasons why your gas prices rise or fall is the fluctuation in the price of crude oil. U.S. refineries buy several million barrels of oil every day to supply the world's biggest economy, so even small price changes make a big difference.
When crude oil prices go up or down, gas prices tend to follow. And right now, oil prices are on the decline.
The price of crude oil has dropped since September as concerns eased about petroleum supplies in the Middle East, according to the U.S. Energy Information Administration.
Oil is again flowing through a critical Libyan pipeline that was shut down earlier this year by striking militias. A U.S. military strike in Syria also appears to be less of a possibility, now that the international community has moved in to eliminate that country's stockpile of poison gas weapons.
Overall, government energy forecasters expect Brent crude oil prices to be lower this year and next year on average than they were in 2012. That means refineries should pay less for crude oil, and at least some of that savings should be passed on to drivers in the form of cheaper gasoline.