Nearly 34 million drivers expected to travel on Memorial Day weekend will be struck with the highest gas prices in seven years after a key pipeline shut down earlier this month.

AAA reported that the current average price of gas as of Friday is $3.04 compared to $1.97 during the same time last year.

Experts said that the surge in prices could be caused by the lack of tank truck drivers to deliver the gas, as well as instances of panic buying by drivers as the holiday weekend gets closer.

“I think we have to worry about prices, supply and crowd behavior,” Tom Kloza, the global leader of energy analysis for the Oil Price Information Service, which tracks gas prices for AAA, told CNN.

And last year, oil and gas prices crashed at the onset of the pandemic, as the coronavirus pushed drivers off of the roads and isolated in their homes. Now, with a swift vaccination rollout and relaxed social distancing measures, more Americans have turned to traveling, especially by car, boosting the demand for fuel prices, which is driving up its price.

Certain parts of the U.S., like the Southeast, could also still be hurting from the widespread gas shortages after a ransomware attack forced the Colonial Pipeline to shut down operations. The pipeline was responsible for fuel production from Texas to the Northeast, so once it closed down, a number of states’ gas supply dried up. 

States like North Carolina, South Carolina, Georgia and Virginia experienced a near gas shortage due to the attack, with other places as far as West Virginia and Kentucky also experiencing the shut down’s effects.

While prices began to level out after the attack, experts suggested that prices could see-saw as more drivers hit the roads across the U.S. for Memorial Day weekend.

Other prices related to traveling are also expected to fluctuate, including airfares and car rentals.

“We don’t expect these higher prices to negatively impact travel for Memorial Day or this summer. There is significant pent-up demand right now and Americans are eager to get out and travel. When travel prices have increased in the past, we find travelers may look for more free activities or eat out less while on vacation, but they still take their planned trips,” an AAA spokesperson told The Hill.

AAA also reported that the number of people traveling by car this year compared to last has increased by 53 percent.

Rachel Bucchino is a reporter at the National Interest. Her work has appeared in The Washington Post, U.S. News & World Report and The Hill.