Gas prices continue their assault on motorists in Western Pennsylvania. According to AAA prices are 20 cents higher this week. The average price per gallon is $4.73. The nationwide average climbed 16 cents per gallon to $4.47 per gallon. Prices are approaching their year high of $4.56 per gallon seen earlier this spring. Here in Washington County we are slightly higher in average price at $4.75 per gallon.