AUGUSTA — Maine may start charging owners of electric vehicles a $250 annual registration surcharge if a bipartisan proposal before lawmakers gets approved.

The proposal is aimed at raising revenues for the state highway fund and making up for gas tax revenue that is lost with the increasing popularity of electric vehicles that don’t rely on gas.

But it is also facing opposition from environmental groups that say the $250 charge is too high and runs counter to efforts to encourage people to buy electric vehicles and help the state meet its climate goals.

“There’s no doubt that electric vehicles reduce our emissions,” said Rep. Allison Hepler, D-Woolwich, the sponsor of a bill to implement an electric vehicle registration surcharge in Maine. “However, their impact on our roads and owners’ responsibility to share the costs of our road infrastructure is what prompted this bill.”

Maine is among 11 states that don’t charge extra registration fees for electric vehicles, while 39 states do, according to the National Conference of State Legislatures. The fees are most often used to fund state transportation systems and can help replace declining gas tax revenues, which have fallen nationally due to the increased presence of electric and hybrid vehicles as well as increased vehicle efficiency, according to the NCSL.

During a public hearing Wednesday on the bill, LD 622, Hepler said the proposed fee was calculated based on figures from the Maine Department of Transportation for the average miles traveled by Maine drivers, the average miles per gallon they get, and the amount of money that a gallon of gas contributes toward state and federal fuel taxes.

In other states, the fees range from a low of $50 in Colorado to a high of $290 in New Jersey, according to the NCSL.

The bill’s sponsors include three Democrats and three Republicans, indicating it could get good bipartisan support when it comes up for votes.

The Maine Better Transportation Association, whose members include municipalities, bus and rail companies, transportation contractors and others, testified in support of the bill but said lawmakers also need to have a broader conversation about funding for the state’s transportation system.

“MBTA supports the intent of this bill, which is to have drivers of electric vehicles help pay for the maintenance of the roads they drive on,” said Maria Fuentes, executive director of the MBTA, in written testimony.

The Maine Municipal Association also testified in support, saying the fee would help fill gaps in needed transportation funding. “Officials recognize the growing need to find alternate sources of revenue to replace the receipts from gasoline tax,” wrote Rebecca Graham in written testimony on behalf of the MMA. “They also would like to make sure there are ways to capture revenue from the visitors using our roadway systems using the same types of vehicles.”

Environmental advocates testified against the bill, saying that there are other reasons for highway fund shortfalls and that a registration surcharge on electric vehicles would discourage potential buyers.

“We are opposed to LD 622 because it would do very little to address the structural problems causing Maine’s transportation funding shortfall, but would create a disincentive for buying an electric vehicle during a critical time in Maine’s climate response,” said Josh Caldwell, who spoke on behalf of the Natural Resources Council of Maine.

Maine moved in 2011 to end automatic inflation-pegged increases in the fuel tax, which Caldwell said Wednesday has led to highway shortfalls.

“EV’s today represent less than 2% of the cars on the road,” Caldwell said. “They are not the primary contributors to road degradation. We are open to seeing EV’s contribute to the highway fund over time, but they are not the cause (of most damage).”

The proposal comes as lawmakers at the federal level are also considering collecting annual fees on electric vehicles.

Lawmakers on the U.S. House Transportation and Infrastructure Committee were expected to take up a proposed $250 annual fee on electric vehicles Wednesday as part of a tax reform bill under consideration, according to Reuters.

Implementing the proposed state surcharge would come with a cost, though it would ultimately increase state revenues.

Maine Secretary of State Shenna Bellows. who testified neither for nor against the proposal Wednesday, said the Bureau of Motor Vehicles would need to obtain and implement a Vehicle Identification Number decoder system to be able to identify which vehicles are electric. Municipalities would also need to update their systems to connect with the state and collect the appropriate information.

A fiscal note on the bill estimates $3.8 million in new highway fund revenue in the next fiscal year and $500,000 in costs for staffing and programming, for a net revenue increase of $3.3 million. Revenue is expected to increase in subsequent years while the costs would drop to about $120,000 annually.

If the bill passes, Bellows wants lawmakers to push implementation to March 1, 2027, to give the state and municipalities time to update their systems.