Although gas prices have been falling for several weeks and even dipped below $3 per gallon in some parts of the country earlier this summer, it appears fuel costs are going up once again.

The Wall Street Journal reports gas prices rose 5.1 percent last week, or approximately 17 cents, according to data compiled by AAA. Drivers can now expect to pay about $3.50 per gallon for gas across the country.

According to the news outlet, the rise in gas prices in the middle of summer is somewhat unusual, as July has typically seen gas prices decline. However, global economic factors coupled with lots of summer driving have pushed prices higher.

"Drivers nationwide saw prices reverse in July after three months of steady declines at the pump," AAA spokesperson Avery Ash told the news source. "Higher global oil prices and increased demand for gasoline during the busy summer driving season were the primary factors that sent pump prices higher in July."

Drivers planning summer road trips need to worry about vehicle maintenance in addition to gas. Getting a car tune up or new tires before a long trip can be a smart way to avoid breakdowns.