Thanks to lower fuel costs and a proliferation of travel bargains, Americans are expected to hit the roads this Memorial Day weekend in bigger numbers than last year.

Last summer’s energy shock drove gasoline prices well above $4 a gallon and forced people to cut back on driving. Then oil prices plunged, and the stratospheric cost of a gallon of gas became a dim memory. But gasoline has been rising rapidly in recent weeks.

Gasoline is selling for an average of $2.33 a gallon, up from $2.06 just last month, according to AAA, the automobile club, and a steep rise from the recent low of $1.67 a gallon in December. A cutback in refining production and the expected rebound in driving this weekend are helping to push up prices at the pump.

Some analysts expect to see gas rise above $2.50 a gallon this summer.

The number of people traveling by car this weekend is projected to rise by 2.7 percent compared with 2008, to 27 million people, according to projections from AAA. Last year, road travel fell by 9.6 percent when prices surged, according to the automobile group.