Reason No. 3: No major disasters
The Gulf of Mexico is home to some of the most promising oil fields in the world. It's also especially vulnerable to hurricanes.
That makes the Gulf a rich and perilous place for satisfying America's energy needs. But the region hasn't seen much hurricane activity in a while, and that has contributed to declining gasoline prices.
A well-placed storm can cripple thousands of oil rigs in a weekend, and occasionally one does. Gas prices usually spike in reaction, as nervous refineries and petroleum traders gauge how long the supply disruption will last.
For example, in August 2012, gasoline prices surged as Hurricane Isaac whipped through the Gulf and shuttered 1.3 million barrels per day of refining capacity. In 2005, gas prices jumped more than 46 cents in the week after Hurricane Katrina made landfall, according to government data.
Mother Nature gave the Gulf a break in 2014. The National Oceanic and Atmospheric Administration says the Atlantic saw only eight named storms, including two major hurricanes, and none of them came near U.S. oil facilities in the Gulf of Mexico.