In the National Transportation Safety Board’s ongoing investigation into Tuesday night’s deadly Amtrak derailment, investigators have found that a technology designed to prevent trains from traveling at dangerous speeds had not been installed on the stretch of track where Amtrak 188 derailed.

The technology, called positive train control (PTC), uses sensors installed on train tracks to automatically slow down or stop a train if one is traveling too fast. The system has been installed in other sections of Amtrak’s Northeast Corridor, NBC Philadelphia reports, “including stretches from Boston to New Haven, New Brunswick to Trenton, and a 30-mile stretch of track in eastern Maryland”—but not in the stretch of track where Amtrak 188 crashed, killing seven people and injuring at least 200 others.

In the days following the derailment, investigators have confirmed that the train was speeding at more than 100 MPH on a curve with a speed limit of 50 MPH. Investigators believe the train’s engineer, Brandon Bostian, pulled the emergency brake moments before the crash; Bostian now claims he doesn’t remember anything that happened.

“We feel that had such a system [PTC] been installed in this section of track, this accident would not have occurred,” the NTSB’s Robert Sumwalt told reporters Wednesday. “Without it, everybody on a train is one human error away from an accident.”

Train systems have been under a federal mandate to install PTC across their tracks since 2008, when a Los Angeles Metrolink train collided with another train, leaving 25 people dead. (The train’s driver was texting.) But as the New York Times points out, implementation of PTC has been slow going, with the prospect of all train systems meeting an imposed 2015 deadline looking unlikely:

Part of the issue is that the technology is complex. Basically, positive train control means that locomotives, engineers and train dispatchers have real-time information about train speed and location, and that trains can automatically respond to sensors along the tracks.

The Association of American Railroads argued as early as 2012 that meeting the 2015 deadline would be a challenge for most of its members because of the high cost of the system and the complexity involved in installing and testing it.

“One major issue,” the Times notes, “is that each freight railroad has its own tools but needs to make sure that its technology can communicate when traveling on tracks owned and operated by others.”


Image via AP. Contact the author at aleksander@gawker.com .