The state gas tax goes up a nickel on Friday bringing it to just under 50 cents a gallon.
A 7-cent gas tax went into effect last August.
According to The Seattle Times, Washington's total gas tax, 67.8 cents — which includes 18.4 cents in federal taxes — ranks second behind Pennsylvania, which collects 68.7 cents.
The hikes were approved by lawmakers last year, to help fund billions of dollars in improvements for the state's transportation system.