"I think it's important that we as Congress be careful not to impose undue regulation on the railroad industry," especially if regulations sap money needed for infrastructure improvements, Thune told a Senate rail safety hearing in June.
Sen. Roy Blunt, R-Mo., one of the bill's three original co-sponsors, has received $201,969 in rail industry contributions. Berkshire Hathaway, the parent company of BNSF, the nation's second-largest freight railroad, donated an additional $45,117. Blunt's chief of staff, Glenn Chambers, is the son of prominent railroad industry lobbyist Ray Chambers. Ray Chambers said he doesn't discuss legislation with his son.
Sen. Claire McCaskill, D-Mo., another co-sponsor, has received $455,995 in rail industry contributions, including $41,768 from Kansas City Southern, which is headquartered in Kansas City, Mo. The third co-sponsor, Sen. Mark Pryor, D-Ark., has received $412,500 in contributions.
The safety system uses GPS, wireless radio and computers to monitor train position and speed and stop them from colliding, derailing because of excessive speed, entering track where maintenance is being done or going the wrong way because of a switching mistake. It's all aimed at preventing human error, which is responsible for about 40 percent of train accidents.
Such a system would be "a game changer" for safety, Joseph Szabo, head of the Federal Railroad Administration, told the Senate hearing.
A dramatic example of the type of accident PTC is designed to prevent occurred in July in Spain when a train traveling twice the speed limit derailed going around a curve, killing 79 people and injuring dozens more.
The NTSB put a newer version of the technology on its "most wanted" list of safety improvements when the list was created in 1990. The government has been funding demonstration projects for decades.
In the Los Angeles-area crash five years ago that prompted Congress to require PTC, investigators said the Metrolink commuter train's engineer was distracted by text messages, allowing the train to run through a red signal — precisely the type of accident the system is designed to prevent. The law gave railroads seven years and three months to install the technology.