The average price of a gallon of regular gasoline nationwide went down in the past 2 weeks. Gas went down from $2.21 per gallon to $2.11, while it was at $2.86 per gallon one year ago. There was large decrease in Illinois as well for the past 2 weeks, as it went down from $2.34 per gallon of regular gas to $2.08. It was also down significantly in Nashville going from $2.19 per gallon of regular gas to $1.94 per gallon.