Gas prices fell for the fourth straight week, AAA Arizona says.

This week, the statewide average shed about 4 cents to $3.41 per gallon of regular gas as of Friday. Nationally, prices fell by a half-cent to $3.54 per gallon.

In its annual Labor Day travel forecast, AAA estimates that that 83 percent of Arizonans traveling for the three-day weekend will do so by car.

Tucson kept the state's lowest average gas price at $3.30 per gallon on Friday, down about 2 cents in a week. Flagstaff had the state's priciest gas, with an average of $3.67 per gallon.