By Steve Goldstein Gas prices are now below $4 per gallon nationally. It's official - gasoline prices are no longer above $4 per gallon. Barely. According to AAA, the national average was $3.9990 a gallon as of Thursday. That is below the $4.56 peak but still well above the sub-$3 average before the U.S. and Israel jointly attacked Iran, which then closed off the Strait of Hormuz to oil-tanker traffic.