A pay-per-mile tax is very likely in the future of Washington state car and truck owners.

It seems a reasonable way to ensure the state continues to collect enough tax revenue to maintain the state highway and transportation system. Currently, the roads are funded by a 49.5 cents per gallon gasoline tax, third highest in the nation. Revenue has been declining, and is expected to plummet further, as more people drive more fuel-efficient cars, hybrids or all-electric vehicles.

Questions, however, remain, including what is the best and fairest way to implement the per-mile tax.

A variety of proposals have been made and studied using pilot projects. The state Transportation Commission will soon start reviewing the results and is expected to vote in December on a recommendation to submit to the Legislature.

An issue that must also be considered is how quickly the current gasoline tax can be phased out or reduced. This is critical to gaining public support for the transition.

Sen. Rebecca Saldana, vice chairwoman of the Senate Transportation Committee, said in an interview with McClatchy Newspapers that a pay-per-mile system would have to be phased in over 10 to 25 years because the state has sold bonds for transportation projects based on revenue from the gas tax. Those bonds would have to paid off before the state replaced the gas tax completely with a pay-per-mile system, she said.

The phase-in could involve, for example, subjecting only newer cars or the highest-mileage vehicles to the pay-per-mile tax. Those motorists would receive a credit on gas taxes they would pay, McClatchy reported.

State lawmakers will have a lot to think about once the recommendation hits their desks — which will certainly be followed by a rash of public comments. People are generally very skeptical when one tax is proposed to replace another over time.

Beyond all this, we believe it is important to find a way to impose a reasonable tax on visitors to Washington state when they use our roads.

Again, none of this will be resolved quickly. Yet, it must be resolved.

The ultimate goal must be to impose a tax system that fully funds the state transportation system and does so in an equitable way. A miles tax must be phased in so that that it eventually eliminates the state’s high gasoline tax.

Editorials are the opinion of the Union-Bulletin’s Editorial Board. The board is composed of Brian Hunt, Rick Eskil, James Blethen and Alasdair Stewart.

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