(Reno, NV) — Washoe County’s gas tax goes up today. It means gas prices will increase by about three-and-half cents per gallon. And, the total cost per gallon from the indexing fuel tax will go up to 57 cents. Today, the average price of a gallon of regular gas in Washoe County is four dollars, 21 cents. The fuel tax went into effect 15 years ago. Since then, it has raised more than 850-million dollars toward maintaining and improving roads. The fuel tax increases every year when the fiscal year starts.