ROBERT SIEGEL, HOST:
We don't know what caused the train to enter the station so fast and to crash. Already there are a lot of questions about whether a technology called positive train control could have prevented it. And for more we turn to Steven Ditmeyer, formerly an official with the Federal Railroad Administration. Thanks for joining us.
STEVEN DITMEYER: I'm pleased to be with you.
SIEGEL: We've learned that positive train control was not installed on this train. Explain briefly what the technology is and whether, if it had been, it might have stopped this train.
DITMEYER: Positive train control consists of transponders placed between the rails, digital data communications, wayside sensors, onboard computer on the locomotive and in the control cabs and control center computers. I believe that this technology could have prevented this accident had it been installed. New Jersey Transit has informed the Federal Railroad Administration that their positive train control system will be implemented by 2018.
SIEGEL: Let's take the worst conceivable case for which there is absolutely no evidence that somebody at the controls of the trained wanted to speed into a station and wanted to crash it into it. Would this system prevent someone from doing that?
DITMEYER: Yes. Positive train control would prevent such an occurrence from happening. The system would know the exact location of the train, and it would know the exact speed restrictions on that section of track. And if the train driver was not obeying that instruction, the onboard computer would automatically bring the train down to the proper speed and stop it at the right location.
SIEGEL: We heard about positive train control after the Amtrak derailment outside Philadelphia last year, and after that there was a big push to get it installed on passenger trains and freight trains. What's happened with that? Is it on Amtrak trains now, for example?
DITMEYER: It is operational now on Amtrak trains in the Northeast Corridor. The federal mandate for positive train control was to have it implemented by the end of 2015. However, last November, the railroads informed Congress and the Department of Transportation that they were not going to be able to meet that deadline. Congress voted to an extension of the deadline to the end of 2018, and that is now the operative timeframe for implementing PTC.
SIEGEL: What would you assume investigators will be looking for as they investigate the causes of this crash?
DITMEYER: The investigators are going to be looking at a variety of things - the wayside signal system to make sure that it was operating. They will be checking the train itself and the train breaks to make sure that they were functioning. They will check the onboard event recorder to see what the locomotive engineer was doing and how he was responding to the signal indications. And finally they will be looking at the engineer himself, interviewing him and trying to determine what he was experiencing and what he believes caused the train to crash into the station. They will be looking at crash worthiness of the passenger cars and seeing how they were damaged and see what caused the injuries to the passengers and to the people on the platforms.
So the National Transportation Safety Board does not rush to judgment on finding the cause of the accident. They want to find the proximate cause, and they want to find the root cause of what caused this accident.
SIEGEL: Steven Ditmeyer, thanks for talking with us today.
DITMEYER: Thank you very much.
SIEGEL: Mr. Ditmeyer is former director of research and development at the Federal Railroad Administration. Transcript provided by NPR, Copyright NPR.