Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Now's the time to go for a drive.

The average price for a gallon of gasoline in the United States fell 13.78 cents in the last two weeks, as refiners continued to pass on lower crude oil prices, according to the Lundberg survey.



The average price of just over $3.38 per gallon was down about 45 cents from a year ago, based on the Oct. 4 survey of some 2,500 retail stations in the lower 48 states, and the two-week drop of nearly 14 cents a gallon was the largest since November 2012, said survey editor Trilby Lundberg.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

(Read more: Gas prices set record: 1,000 days above $3 a gallon)

But drivers should enjoy it while they can since "the price declines might be coming to an end right now," she said.

When crude oil prices slipped substantially in early September, it allowed refiners to cut their prices to retailers. "But crude prices changed very little in this last two-week period," Lundberg said. "The margins for both refiners and retailers have both skinnied, so I doubt they'll be able to continue their price cutting."

It would take another significant decline in crude oil prices "to allow price decreases at the pump to continue," she said. "I think we will not see further declines at the pump without that."

(Read more: Fuel cell firms resurgent after early hype)

St. Louis had the least expensive gasoline in the country at $3.01 per gallon, according to the Lundberg survey, while drivers in San Francisco -- often the country's priciest gasoline market -- again paid the most, at $3.88 per gallon.



