Gas prices could top $5 a gallon by this spring

Gas prices have been spiking in the Bay Area recenlty, with prices hitting $4 a gallon at many pumps around the region.

In fact, a Shell station near San Francisco International Airport was selling regular unleaded for $4.05 a gallon and supreme for $4.27. And prices are expected to climb even higher.

Oil prices shot up 4.2 percent Tuesday, climbing to just under $103 a barrel.

Iran is being blamed by many for the sudden spike. Faced with sanctions over its nuclear program, Iran is threatening to shut down the Strait of Hormuz.

"A sixth of the world's oil goes through the Strait of Hormuz. Iran militarily isn't strong enough to control the strait if it came down to that, but it is strong enough to create a lot of instability," explained U.C. Berkeley Professor Harley Shaiken.

Karim Sadjadpour of Carnegie Endowment had words of caution for the U.S.

"There is a concern that the hard-liners in Iran will try to provoke some type of military attack on themselves for domestic political expediency," said Sadjadpour. "And that's a trap which the United States and Israel should be careful about walking into."

Gas prices start the year with a national average of $3.28 a gallon. That's the highest level ever at the beginning of a year.

In South San Francisco, the price is even higher.

Jacob Martinson of Pacifica paid $4.12 a gallon for diesel fuel. "My tank it's pretty big. It's like an 18 gallon tank. So at $4 it'll take about $75 to $80 to fill up."

Even filling up a motorcycle cost more than $20.

"It's still expensive. Obviously the savings are a little better, I get about 40 miles to the gallon," said Marty Boone of Vallejo.

Global demand for oil is expected to set a record this year and a disruption could hurt everyone.

"70 percent of our economy depends on consumer purchases and anything that rattles consumer confidence, including what you pay sticker shock at the oil pump is something that the economy just doesn't need right now," said Shaiken.

Forecasts call for gas prices to inch upward this winter and potentially skyrocket this spring to almost $5 a gallon.