The National Park Service and Federal Highway Administration have given Alexandria clearance to build a Metro station in the city’s growing Potomac Yard community.

After a series of delays, the federal agencies signed a Record of Decision this week supporting the construction of the Potomac Yard Metro station, a project that the city says is needed to increase transportation choices and accelerate transit-oriented development.

Alexandria can now move into design and construction of the $268-million Metro station, slated for a 2020 opening.

“The federal environmental approval we have received takes us a big step forward,” Mayor Allison Silberberg said in a statement. She said the project is key to the city’s vision “for Potomac Yard as an attractive, walkable and economically vibrant community.”

The federal approval was the final piece the city needed to move the project forward. Alexandria will fund the project but the Washington Metropolitan Area Transit Authority will oversee the construction. Metro is expected to award a contract next summer and construction could begin in late-2017, city officials said.

The Potomac Yard station will be built on Metro’s Yellow and Blue Lines, between the existing Braddock Road and National Airport stations. It is expected to boost mass transit along the Route 1 corridor and facilitate growth at Potomac Yard, a 295-acre former railroad yard that is being transformed into an urban center.

The station is planned just east of the existing Potomac Yard Retail Center, on a site that intrudes on the George Washington Parkway’s scenic easement, but would best meet “the project purpose and need.”

The Metro station, the federal report signed Tuesday says, will create opportunity for smart growth in the region.

“The project will maximize the number of people that can utilize public transit to and from the Potomac Yard area, noticeably decreasing of the number of cars from adjacent roadways,” the federal document says. “The NPS concurs that this project will serve as an overall benefit to the surrounding community and Metro ridership as a whole.”

The station will generate an estimated 11,300 weekday boardings and shift as many as 6,700 daily vehicle trips to transit by 2040, according to project documents.

City officials say the transit station, which has been in Alexandria’s plans for more than two decades, will generate billions of dollars in new private-sector investment and accelerate growth in an area that has seen the construction of hundreds of rowhouses and apartments in recent years.

According to projections, the project will result in $1.5 billion in net revenue to the city over 40 years. Once the area is completely developed, it is projected to produce about $98 million in annual revenue that could be used to pay for city services and amenities.

The project is anticipated to be funded through a variety of sources, including new tax revenue primarily from development around the station, regional transportation authority grants, developer contributions, and revenue from a special tax district.

The Record of Decision concludes a federal environmental review process that lasted about five years. During that time the city negotiated an agreement with NPS to settle the impact on the Parkway. Through the agreement the federal agency will release the easement on city land where the station will be located and the city will transfer some local parkland near the parkway to the federal government.

NPS establishes the land exchange and other conditions in the Record of Decision, and said the city and Metro are committed to minimize impacts on the Parkway and mitigate the loss of park.