The US Federal Railroad Administration (FRA) has approved the construction of the new Baltimore/Washington International Thurgood Marshall Airport (BWI) rail station.
The project would add a fourth track to nine miles of the Northeast corridor surrounding BWI, as well as reconfigure the platforms to allow boarding from all four tracks.
Last April, an environmental assessment was launched to determine if carrying out the project would cause any negative impacts and now the FRA has issued a finding of no significant impact (FONSI) for the project.
The FONSI will allow the Maryland Department of Transportation to secure funds for final design and construction.
Transportation secretary Anthony Foxx said: "The current rail station and infrastructure at BWI was built more than 30 years ago and does not support today’s needs or the region’s expected growth.
"The completion of the environmental review for this project brings BWI one step closer to a safer rail station, reduced rail congestion and increased reliability."
Both Amtrak and Maryland Area Regional Commuter (MARC) trains provide passenger-rail service at the station, where ridership by daily commuters and airline passengers has been increasing.
There are currently only three tracks between the Grove and Winans, while the addition of a fourth track would increase rail capacity and reliability.
FRA administrator Sarah Feinberg said: "A new BWI rail station will allow both airline and rail passengers to get to their destinations safely, reliably and efficiently."