Virginia’s average gas prices rose by a penny over the past week according to price tracking website GasBuddy. The average is $3.15 a gallon which is just under a nickel lower than a month ago but around 85 cents more than a year ago. The lowest price is $2.75 a gallon while the highest is $3.89 a gallon. Meanwhile the national average for a gallon of regular is up over a penny to $3.31.