Gas prices hit a national average of $3.74 a gallon for regular unleaded — and are approaching $4 in the city, with no end in sight for outraged drivers.

Regular was selling for an average of $3.45 a month ago but has been pushed up by 24 straight daily increases, the AAA said yesterday.

“This is crazy. This is ridiculous,” driver Marvin Calvin, 55, of Brooklyn, said as he paid $30 for $3.99-a- gallon regular at a Shell station in South Williamsburg.

“We’re not at war, so why is gas so high?” he wondered.

Industry analysts say the answer is the rising price of oil — up 10 percent in just a month — and uncertainty over Iran’s threat to close the Strait of Hormuz, through which 20 percent of the world’s oil is shipped.