Talk of stopping the annual increase in Maine’s gas tax has become as predictable as July thunderstorms. But, where the rain helps gardens grow, the gas tax posturing doesn’t help the state’s drivers. Instead of an annual rehashing of the gas tax, lawmakers should use their time and energy to find – and support – better ways to fund the state’s roads.

Legislators are right that gasoline prices, which are up more than $1 since last year, are hurting Maine residents. The eight-tenths of a cent increase in the state’s motor fuel taxes that went into effect on July 1 is a tiny piece of that problem.

Still, Rep. William Browne of Vassalboro, the ranking Republican on the Legislature’s Transportation Committee, called the automatic increase “onerous.”

Some perspective: generously rounding up, the 1-cent per gallon tax increase will add less than a quarter to the cost of filling up the tank of an SUV (less for a smaller car with a smaller gas tank). That’s enough for a gumball, but not for tax relief.

More important, the gas tax is a critical source of money for road work. Highway projects are funded with federal dollars, bond issues and the state’s highway fund. Nearly 70 percent of highway fund revenue comes from the state’s fuel taxes. The state’s gas tax – which is 28.4 cents per gallon of gasoline and 29.6 per gallon of diesel – has failed to keep pace with repair and maintenance needs and costs.

Because of this shortfall, the Legislature’s Transportation Committee last year looked at new ways to fund road and bridge work. Alternatives, such as tolls on the state’s interstate highways and switching to a sales tax on gasoline (which would rise much more rapidly with recent price increases than the current excise tax indexed for inflation) were dismissed because they were politically unpopular. That leaves the state still reliant on a shrinking revenue source – and one that lawmakers routinely threaten to shrink even more. Not allowing the July 1 increase would decrease revenue by nearly $7 million this year.

The good news is that Maine gets a lot out of its road spending. The state annually receives a fairly high ranking for the cost-effectiveness of its road work. One way it saves money is by repairing roads and bridges that should be replaced and patching roads that should be rebuilt. As a result, the share of the DOT budget dedicated to maintenance is among the highest in the country.

No matter how efficiently it used it, the department must get the money from somewhere. Until lawmakers agree on alternatives, that somewhere is the gas tax. “Politically, none of us like it,” Rep. Boyd Marley, House chair of the Transportation Committee, said of the annual tax increase. “But responsibly, that’s the only way we’ll fund roads and bridges.”

Responsible and politically popular often don’t lead to the same place. In this case, the responsible road is the better choice.