The recent Pennsylvania train collision involving three Norfolk Southern trains sheds light on deficiencies within the automated braking system intended to prevent such incidents.

The National Transportation Safety Board's preliminary report reveals that none of the circumstances leading to the derailment on March 2 would have activated the positive train control (PTC) system to halt the trains. The system was unable to prevent the second train from colliding with the stationary one, nor could it stop the third train from hitting the derailed cars obstructing its path moments later.

Railroad safety expert Chris Barkan acknowledges that PTC is not generally designed to address such scenarios.

Mandated by Congress after the tragic 2008 Metrolink-Union Pacific collision in California, the PTC system took over a decade and significant investment to develop. However, it only functions under specific conditions.

In the Pennsylvania crash, despite the eastbound train slowing down after passing a restricted speed signal, the absence of a stop signal meant the braking system remained inactive.

Following the initial collision, the obstructed track led to another collision with the third train, further illustrating the limitations of the PTC system. The system relies on signals from the railroad and cannot detect obstacles on the tracks. Moreover, given the tight time frame between the collisions, stopping the third train would have been challenging regardless.

The incident resulted in minor injuries to crew members and damage estimated at $2.5 million. Norfolk Southern has refrained from commenting on the NTSB's findings, with the final report expected to take over a year to complete.

The NTSB's ongoing investigation will scrutinize the railroad's protocols and training procedures. Norfolk Southern's safety practices have faced scrutiny since a previous derailment in Ohio in 2023.

Federal regulations mandate trains to operate at restricted speeds, accounting for visibility conditions. However, the NTSB's report did not specify if weather conditions affected visibility or if terrain features impeded crew visibility.

Barkan emphasizes the importance of adhering to restricted speed regulations, highlighting previous collisions resulting from failure to observe these protocols.