Nearly a week after the United States and Israel launched attacks on Iran, motorists are starting to feel the fallout at the gas pump as the conflict spreads across the Middle East.

Prices have increased approximately 30 cents a gallon across northern Illinois.

According to GasBuddy.com, the price for a gallon of gasoline ranged from $3.29 to $3.39 Friday morning in Kankakee, Bradley, and Bourbonnais. In Streator, where gas sat at $2.89 for weeks, it has risen to $3.24, a price that’s steady from Peru to Ottawa to Marseilles.

Travelers along Interstate 80 will see even higher prices once they hit Joliet, where prices have risen as high as $3.69, though traveling off the well-worn path of the interstate does show a few stations still selling gasoline at $3.13.

The Joliet area seems to be the outlier for high prices in northern Illinois, though. DeKalb County, going east to the suburbs, including into McHenry and Kane counties, stays consistent, if not a tad cheaper than the Illinois Valley, ranging from $3.14 to $3.69.

As of Friday morning, the price for a barrel of oil had moved north of $90, and according to the Associated Press, it could be going higher.

If oil prices spike further, like to $100 per barrel, and stay there, some analysts and investors say it could be too much for the global economy to withstand, the Associated Press reported, which cites an earlier interview with Hakan Kaya, senior portfolio manager at investment management firm Neuberger Berman.

The Strait of Hormuz, a strategic waterway between Oman and Iran, is the world’s most critical chokepoint, according to the U.S. Energy Information Administration (USEIA).

Approximately 20% of the world’s total oil consumption passes through this narrow strait daily, according to the USEIA.

A Shaw Local story from March 3 pointed out that while the U.S. is the largest economy in the world, it still depends on oil and gas from other countries.

As of Friday, no tanker traffic is entering or leaving the strait.

“It’s not been necessarily closed, but the elevated risk has caused vessels to drop anchor before sailing through the Strait of Hormuz on the uncertainty that Iran could potentially launch attacks on vessels transiting through the Strait of Hormuz,” Patrick De Haan, head of Petroleum Analysis at GasBuddy said last week shortly after the attacks began. “Again, confidence is the name of the game when it comes to the Strait of Hormuz. Nobody really has confidence right now to transit through the Strait, and that’s why oil prices are reacting. This uncertainty comes as gas stations in several states, including Illinois, switch over to the more expensive summer blend.”

De Haan said summer gasoline is more costly, but the good news is there hasn’t been a major impact on the wholesale price of gasoline.

“Some states engage in what we call price cycling, which is a pattern of large increases followed by large decreases,” De Haan said. “These states include areas of the Great Lakes, Michigan, Indiana, Ohio, Illinois, Wisconsin, and Kentucky. Also, states like Texas and Florida, as well as areas of Colorado, exhibit these patterns where gas prices jump up then very quickly start to decline.”

De Haan said those markets are already seeing increases.

“It’s the typical cycle timing, but the cycle amount is enhanced by what’s happening overseas. That is, last time these states saw prices cycle, they are now cycling to prices that are approximately 20 cents higher than the last time they cycled.”

Much of that is due to the oil market’s reaction to the attacks on Iran, De Haan said.

According to the Associated Press, the U.S. stock market has a history of bouncing back relatively quickly following conflicts in the Middle East and elsewhere, as long as oil prices don’t jump too high for too long.