Virginia Gov. Ralph Northam (D) has proposed raising the state’s gas tax by 4¢ to address looming highway and bridge maintenance funding shortfalls.

Expected to generate as much as $1 billion over the next four years, the revenue will also help to support a $3.7-billion statewide passenger rail expansion plan announced in December that includes constructing a new bridge over the Potomac River and nearly 40 miles of new track improvements.

The proposal would also direct $200 million to the state’s Smart Scale project prioritization program, accelerate more than $2 billion of projects along the I-81 corridor and augment current subsidies to the Washington, D.C., Metro subway system.

At 16.2¢, Virginia’s statewide gas tax is among the lowest in the U.S., unchanged since the mid-1980s. If approved by the state legislature, the hike could take effect in July