CSX, which reports earnings Tuesday, is one of several major railroads asking Congress to extend a deadline to install a new safety system.

The system, called Positive Train Control, uses GPS to track where trains are and prevent collisions and derailments.

Rail carriers that transport passengers or hazardous materials have until the end of the year to install it. Larry Mann, a rail safety attorney, said the railroads have been dragging their feet.

“It’s a matter of the railroads willing to put the assets into building it,” he said.

The freight rail industry will have already spent about $6 billion on the system by year’s end, according to the Association of American Railroads.

Larry Gross, a consultant with FTR Transportation Intelligence, said installing the system, which he calls an unfunded mandate, has been complex. He doubts railroads will get a return on their investments.

“In other words, it doesn’t pencil out as a net economic benefit,” he said. 

Gross said the costs associated with the system are a drag on railroads’ finances. Still, he acknowledged the bigger issue for freight carriers has to do with the commodities marketplace and lower demand for transporting coal.