(CNN) - Good news at the gas pump - gasoline prices fell more than 6 cents per gallon in the past two weeks, according to a national survey of about 7,000 gas stations nationwide.

The Lundberg Survey's average nationwide price of a gallon of self-serve regular fell 6.4 center per Gallon, to $2.15 per gallon, said publisher Trilby Lundberg.

"The all-time record high, unadjusted for inflation, was on April 8 when a gallon of self-serve regular was $2.2888" -- a 50 cent rise from the beginning of the year, she said. "Since then the drop has been just under 14 cents."

Prices are likely to fall further before leveling off, Lundberg said.

Accounting for part of the drop, she said, is the price of crude oil, which hit an all-time high of $55.39 per barrel on April 22, and has since dropped to $46.80 -- also about a 14 cent per gallon fall.

Supplies are plentiful as well, she said, driven by "the return of some idled refinery capacity." In preparation for the summer peak driving season, refiners must idle some capacity for maintenance and repairs.

Also, Lundberg said, imports have been strong.

"For the near future, gasoline prices are likely to lose a few more cents per gallon -- as much as nickel or more because supplies of both crude and gas are plentiful," she said.

The Lundberg Survey found the highest average price per gallon for self-serve regular in San Francisco at $2.51 and the lowest in Jackson, Miss., at $1.94. Other selected cities:

-- Atlanta $1.96

-- New Orleans $1.99

-- Houston $2.00

-- Detroit $2.04

-- Baltimore $2.10

-- Boston $2.18

-- Salt Lake City $2.21

-- Honolulu $2.44

-- St. Louis $1.96

What's driving gas prices? Check out our Oil Crunch 2005 special here.