Buckle up, America. Gas prices have a hit a level not seen in three years and are expected to continue their upward trajectory. The national average for a gallon of gas reached $2.82 this week, a level not seen since summer 2015, according to online gas station database GasBuddy.com. Californians are paying the most: $3.61 per gallon. By contrast, Oklahoma has the lowest state average, at about $2.50.

A customer pumps gasoline into his car at a service station in San Francisco. Getty Images

While gas prices typically head higher every spring due to increased driving demand, the current average is 48 cents more per gallon — an increase of about 20.5 percent — than the $2.34 consumers paid a year ago before prices inched downward. For most of summer 2017, the average price hovered around $2.30 or trended lower. The summer months will likely bring even higher prices. "While it won't cost motorists as much as it did during 2011 to 2014 [when national averages ran $3 to $4], it will cost them millions more every day versus last year," said Patrick DeHaan, senior petroleum analyst for GasBuddy.com.

If the higher prices pinch your budget or affect your vacation plans, there are ways to save money on gas. For starters, shop around. Depending on where you live, there can be big price swings between gas stations. For instance, a recent review of the Los Angeles area found a difference of about $1 per gallon between the highest- and lowest-price stations, DeHaan said. While the difference in price per gallon may only be a few pennies, it still adds up. "Even if it's a difference of a nickel or dime, that could become a couple hundred dollars in savings," DeHaan said.