Gas prices are a slight bit lower in Western Pennsylvania according to AAA. This week gas prices averaged $3.63 per gallon. Last week they were $3.64 per gallon. Nationally, gas prices are $3.53 per gallon, two cents less than a month ago. Last year, drivers were paying $1.28 more per gallon. In Western Pennsylvania, drivers last year were paying $4.93 per gallon of gas.