The District of Columbia received a $2.9 million federal grant Monday to study rehabbing or replacing the Long Railroad Bridge over the Potomac River.

According to the U.S. Department of Transportation, the bridge is more than 100 years old and is the only rail link between Virginia and Washington, “carrying approximately 90 passenger and freight trains daily.”

Officials said traffic is expected to grow by more than 50 percent over the next 20 years. CSX, which owns the bridges, is expected to pay $100,000 toward the cost of the study.

Transportation Secretary Ray LaHood said the work is part of a plan to create a Southeast High-Speed Rail Corridor linking Atlanta and Charlotte with Washington. He also announced that the Georgia Department of Transportation received a $4.1 million grant to study a link between Atlanta and Charlotte.

“With America’s population set to grow by 100 million over the next 40 years, high-speed rail will play a vital role in reducing congestion and meeting America’s long-term transportation challenges,” LaHood said in a statement.