SAN DIEGO -- The average price of a gallon self-serve regular gasoline in San Diego County fell Friday for the 13th time in 14 days, declining six-tenths of a cent to $2.975.

The average price is 3.9 cents less than a week ago and $1.601 less than a year ago, but 16 cents higher than last month, according to figures provided by the AAA and Oil Price Information Service.

The average price had fallen 11 consecutive days, then rose one-tenth of a cent Wednesday, resuming its decline Thursday by four-tenths of a cent.

"Prices are dropping very slowly, but they haven't been this low for Independence Day since 2005 when pump prices were averaging about $2.50 a gallon," Jeffrey Spring of the Automobile Club of Southern California said.

"For the projected 2.3 million Southland car travelers that will take holiday trips this weekend, the gas price decrease -- along with numerous travel deals -- will give vacationers a lot more for their money this year."