Gas prices inched up in the last week in New Jersey, reflecting a national trend.

A gallon of regular unleaded gas in New Jersey rose a penny to $2.29. That's an increase of 45 cents from a year ago. The state implemented a 23-cent gas tax hike last November.

AAA Mid-Atlantic says the current increase is due to a shift to summer-grade blends and to the rising price of crude oil. Crude reached $50.70 per barrel on Friday, compared to $48.05 a week earlier.

Nationally, a gallon of unleaded rose two cents to $2.31 last week, an increase of 25 cents over a year ago.

AAA says gas prices could increase as much as 40 cents per gallon this summer, but hopefully will stay under $3 per gallon.