Virginians are buying less gas but driving more miles. For transportation officials, that’s a problem.

Motor fuels taxes are the third-largest non-federal source of transportation funding in Virginia, generating $857.2 million out of $3.4 billion in state revenues for fiscal 2018, according to VDOT, behind retail sales taxes and taxes on vehicle sales.

The state has convened a task force to study declining fuel tax revenues and suggest potential solutions. Eventually, that could involve moving to a system that charges road users based on how many miles they drive, not how much gas they consume. In the near term, policymakers may consider tweaking the gas tax rate, which currently works out to 22 cents per gallon, or exploring other taxes and fees.

The task force is scheduled to issue recommendations later this year.