The U.S. Justice Department filed suit against Norfolk Southern on Tuesday, alleging the railroad has caused delays on Amtrak’s route that passes from New York City through Atlanta to New Orleans.

The civil complaint filed in U.S. District Court in Washington, D.C., alleges Atlanta-based Norfolk Southern is required by federal law to give Amtrak passenger trains preference over its own freight trains, but that it “regularly forces Amtrak trains to follow behind slower freight trains instead of allowing Amtrak trains to pass.”

Norfolk Southern issued a statement in response saying it “has taken a leading role in the industry to expand passenger rail service.”

“We are committed to complying with the law, working together, and honoring our commitments,” Norfolk Southern said. “Over the past several months with Amtrak, we have focused on the on-time performance of the Crescent passenger train. We hope to resolve these concerns and continue to make progress together.”

U.S. Transportation Secretary Pete Buttigieg said in a written statement that the federal requirement for freight rail companies to give Amtrak preference has existed for half a century, “yet compliance with this important law has been uneven at best.”

According to the federal government, only 24% of southbound trains on the Crescent route arrived on time in the 2023 federal fiscal year. It said Norfolk Southern controls 1,140 miles of the 1,377-mile Amtrak Crescent route and handles dispatch for all trains on that segment.

The lawsuit gives examples of delays, including a reported delay of nearly an hour of an Amtrak train behind a slow freight train outside of New Orleans, and another in which an Amtrak train had to wait for more than an hour while three freight trains passed, according to the complaint.

“Norfolk Southern regularly operates freight trains on the Crescent Route that exceed the length of any siding that Norfolk Southern has built or maintained on that route,” the lawsuit says. “These long freight trains cannot move into a siding to allow a faster-moving Amtrak train to pass, thus forcing the Amtrak passenger train behind them to operate at slower speeds, causing delays to Amtrak passengers.”

Norfolk Southern’s network is primarily in the eastern part of the United States, but that’s not the only region where Amtrak trains run late more often than desired. None of Amtrak’s long distance routes met the Federal Railroad Administration’s 80% on-time standard last year, with Amtrak saying: “Waiting for freight trains is the largest cause of delay to passengers.”

Amtrak’s website also says that “many freight railroads ignore the law because it is extremely difficult for Amtrak to enforce it, and as a result, people and the American economy suffer.”

The Rail Passengers Association issued a statement Tuesday saying the Justice Dept. had not taken such enforcement action since 1979.

“That means tens of millions of American passengers have been waiting for decades for relief from these host railroad-caused delays,” said Rail Passengers Association President Jim Mathews in a written statement. “With that history in mind, Rail Passengers is extremely appreciative of the leadership shown by the Biden Administration, the DOJ, and the U.S. Department of Transportation for taking action to protect the legal rights of passengers to quality, on-time service.”