The FRA has agreed to modify the rules in consolation with rail companies, but it has not said what changes it would make.
Brown said Thursday that cost should not be the primary concern.
"I think this committee needs to careful about what it does with respect to rail safety," she said according to prepared remarks released by her office. "Serious accidents, injuries, and fatalities continue to occur. In fact, human error remains one of the leading causes of rail incidents, and according to the Government Accountability Office, the number of fatalities has spiked over the years as a result of specific incidents, including one in South Carolina, another in North Dakota, several in Texas, and of course the tragic accident in California.
"I would hate for another tragedy to occur like the one in California," she continued. "As the economy grows and high-speed and intercity passenger rail are developed in this country, we have to stay focused on improving rail safety."
The PTC requirement was included in a Rail Safety Improvement Act passed in 2008, and signed by former President George W. Bush. The measure was approved in the wake of a deadly collision between a passenger train and a freight rail in California that killed 25 people.
Railroads, Pipelines, and Hazardous Materials Subcommittee chairman Rep. Bill Shuster (R-Pa.) acknowledged that accident was tragic. However, he still called PTC a regulatory overreach Thursday.
"Throughout our government, I am deeply concerned with the regulatory overreach that cripples our economy, stifles job creation, and ties our nation up in red tape," he said in a statement. "“Positive Train Control is an example of regulatory overreach that I would like to focus on here today. FRA’s PTC rule has raised great concern and strong objections, specifically because the FRA regulation appears to have gone beyond the scope of the Rail Safety Improvement Act PTC mandate."
This story was posted at 11:53 a.m. and updated at 1:23 p.m.