AAA Carolinas says the average price of gas in the state has jumped 15 cents in the last month from $3.38 on March 8 to $3.53 on Tuesday (yesterday). The auto club says North Carolinians are paying the highest price for gas since last July. AAA Carolinas says the spring is tough for drivers because that’s the time when gas prices rise because of refinery maintenance; plus the tightened supply across the country had led to the higher prices. In spite of the increase, the March average of $3.40 is the lowest monthly average for March since 2010. Gas prices are expected to continue to rise until refinery maintenance is complete, likely by the end of April. Although demand continues to rise with warmer weather, increased production will allow supply levels to keep up with demand. Overall, AAA Carolinas expects gas prices for 2014 to be slightly cheaper than 2013, barring any unforeseen developments.