Last week saw another week of rising gasoline prices across much of the United States, with the national average rising just a little over a penny per gallon to $3.55/gallon. That remains under last year's $3.58/gal on the same day, and is the highest since September 13, 2013.

The six month trend chart is starting to show a slowdown in the increases, however. Nationally, prices began to rise around February 7, and have been on an upward trajectory since then. However, the spike began cooling in mid-March, with prices rising just 8-cents a gallon over the last month.

It looks as it will be increasingly unlikely that the national average hits the $3.83/gallon that GasBuddy had forecast for the spring last December.

Meanwhile, Canadian prices have been coming down slightly since peaking March 5th. Average prices in Canada are down to 131c/L, virtually the same as a week ago. But over the last month, prices have come down 1.4c/L across Canada.

The cheapest states to find gasoline remain the staples- Utah, Montana, South Carolina, New Mexico, and New Jersey.

In the last week, Chicago surged past $4/gallon for the first time since July of last year. The rise is blamed partly on a temporary surge in ethanol prices that now has shown signs of relief. Chicago may dip back under $4/gal this week.

Around the nation, prices could drop slightly as ethanol prices have contracted as rail network congestion has eased. By next week, the national average may dip a penny or two per gallon.