(December 9, 2014) The average price of a gallon of gasoline in the United States has dropped nearly a dollar since early May, the lowest price in more than four years, according to the Lundberg survey released Sunday.

Lundberg said prices for regular-grade gasoline fell to $2.72 a gallon on average nationwide, down 12 cents since the last survey two week ago.

The decline in prices was driven by slower demand coupled with dramatic growth in oil supply production, especially in North America and Canada. The strengthening U.S. dollar also played a role.

"We may see a few more pennies drop before Christmas," said the survey's publisher, Trilby Lundberg. "All this presupposes that crude oil prices don't bounce up significantly in the near future."

The highest price within the survey area in 48 U.S. states was recorded in San Francisco at $3.04 per gallon, with the lowest in Albuquerque, at $2.38 per gallon.

Source: Press reports