Maryland and Virginia are partnering to expand the American Legion Bridge, one of the worst chokepoints in the region, Maryland Gov. Larry Hogan and Virginia Gov. Ralph Northam announced Tuesday.

The project aims to rebuild the existing eight lanes and add two new Express Lanes in each direction, creating a 12-lane bridge. Hogan said the expansion will ease traffic, bring cleaner air, and better quality of life.

The bridge would be funded through a public-private partnership, similar to Virginia’s other High Occupancy Toll lanes. Maryland Transportation Secretary Pete Rahn said they hope to break ground in 2022, but the project must get through environmental studies and approval from Maryland’s Board of Public Works and Virginia’s Commonwealth Transportation Board.

Hogan and Northam dubbed the project the “Beltway Accord” during a surprise announcement made at Tuesday morning’s Capital Region Transportation Forum, but many details are still to be determined. 

Maryland, which owns 79 percent of the bridge, will take the lead on the bridge project. Virginia owns 21 percent of the bridge, but each state will pay half of the billion-plus dollar cost.

Hogan and Virginia Transportation Secretary Shannon Valentine touted the project as a “once-in-a-generation” endeavor for the region.

The governors say the expansion is projected to cut commuting time in half for many travelers, cut congestion in the bridge’s regular lanes by 25 percent.

No homes in Maryland or Virginia will be affected by the bridge project, state releases said.

The project would include pedestrian and bike access. Transit agency buses would be able to use the Express Lanes, but officials are not including rail access. 

Many transportation planners say expanding highways induces more traffic. But Rahn said price-managed lanes paired with free travel for two or more in a car are a way to de-incentivize solo driving. Rahn says new express lanes will open up the Beltway to transit, too.

“You don’t see buses on I-495 or I-270 (now) because it’s not reliable,” Rahn said. Private buses will still have to pay for use. 

The American Legion Bridge opened in 1962, but the states say it’s been operating beyond its capacity for nearly four decades. More than 235,000 vehicles cross the bridge daily. 

“More than 40 percent of the region’s population travels this segment of the Capital Beltway, and the region expects to grow by another 1.2 million people by 2040,” Virginia’s press release said. “Both governors have made it a top priority to identify a long-term, seamless solution for the Capital Beltway.”

Maryland is also building High Occupancy Toll lanes from the Potomac River to I-95 North interchange to Baltimore. Virginia is finishing a 90-mile HOT lane network.

This story originally appeared on WAMU.