The state’s system for raising road-maintenance revenue is at odds with local energy policy and national trends. Hawaii is pursuing a renewable-energy future and as a result is encouraging the adoption of electric vehicles and EV chargers as part of its Clean Energy Initiative.

Across the automotive industry, regulatory pressures have resulted in much more fuel-efficient cars rolling off the production line.

The consequence of all this fuel-saving, officials have said, is that commuters are buying less gas and paying less per-gallon fuel taxes than they once did. And just at the point at which highway repair needs are high, the tax revenue to cover the cost is falling.

So — with an eye on the experience in Oregon, where a pay-by-the-mile system was enacted in 2013 and launched two years later — the state is exploring instituting a road usage charge (RUC) here as well.

Replacing the fuel tax with an RUC is an intriguing idea, worthy of consideration. It’s logical that the more a taxpayer uses a public facility, the more support for its upkeep should be owed. The more miles driven, the higher the tax. Car owners could exercise some control over their tax burden by driving less.

It also could be a fairer system.

According to a 2016 feasibility study conducted for the state, drivers of less-fuel-efficient, low MPG (miles per gallon) vehicles typically live in rural areas, especially on the neighbor islands.

Drivers of less-fuel-efficient cars shell out more for gas and the per-gallon tax. While larger vehicles arguably put more wear and tear on a road, the tax burden is disproportionately high.

Further, EV drivers do not pay; they should be part of the tax base that supports the roads they use.

The state DOT has turned to the public to gather reactions to the RUC concept. But the agency has been pursuing it for some time. In 2016, DOT submitted an application to the Federal Highway Administration and received a grant for just under $4 million to develop and study a road-usage tax system for the state.

“A key question for research is how could a per-mile fee affect purchase and use of high MPG (mile-per-gallon) and alternative fuel vehicles, which are critical to Hawaii’s energy independence objectives,” according to the proposal.

The system would draw from the state’s existing vehicle safety inspection program, which already collects and records odometer readings for vehicle registration.

Among the knottier questions the RUC studies will have to answer is how — or if — rental-car-driving tourists would contribute toward the upkeep of roads under such a system. More than 200,000 visitors are in the islands at any given time, and that constitutes considerable strain on the roads. Would visitors be accountable for their odometer mileage, as residents are? Oregon addresses the problem by charging both the RUC and fuel tax. Visitors pay only the fuel tax, and residents automatically have their fuel tax payments deducted from their RUC.

The DOT community outreach began in August with focus groups and phone surveys and now is scheduling meetings statewide. The project website (hiruc.org) has information on the meeting schedule, as well as an online poll to gauge public opinion informally.

The challenge for policymakers is that the general public may see the RUC as a new tax rather than a replacement for the fuel tax. Certainly, the state should not impose an undue tax burden on already burdened taxpayers. An RUC should be used to spread the pain more evenly, not just increase it.