This life-saving technology was not available on the derailed Amtrak train

Thomson Reuters

FILE PHOTO: Rescue personnel and equipment are seen at the scene where an Amtrak passenger train derailed in DuPont

• Amtrak Cascades train 501 derailed near DuPont, Washington on Monday.
• The train was going 80 mph in a 30 mph zone.
• The train was not equipped with positive train control.
• PTC technology can automatically slow down trains traveling at too high a speed.

On Monday, Amtrak Cascades train 501 derailed near DuPont, Washington. The incident resulted in the deaths of three passengers and the shut down of the southbound lanes of Interstate 5.

According to the National Transportation Safety Board, onboard data showed the train traveling at 80 mph at the time of the derailment; 50 mph above the 30 mph speed limit.

It's a tragic incident that could have possibly been prevented with the help of a safety system called positive train control (PTC).

The section of track where Monday's derailment occurred was equipped with PTC, a spokesman for the track's owner, Sound Transit told CNN. But, the system was not yet operational because it had not yet been installed on the trains, according to the report. In fact, PTC won't be fully operational on this segment of the track until the second quarter of 2018.

So what is positive train control?

PTC systems are made up of three elements: an onboard system that monitors the locomotive, a wayside system that monitors track conditions, and a ground station server.

Using satellites, PTC technology has the ability to send warnings to those in control of the train. If there's no response, the tech can automatically slow down or even stop trains that are moving too fast or approaching a dangerous area at too high a speed.

To function properly, PTC systems must gather and analyze data on the train's stopping distance (weight and length); track composition and geography; train speed; and authorizations, the Association of American Railroads explained on its website.

According to the Federal Rail Administration, the system is designed to "reliably and functionally" prevent train-to-train collisions, derailments caused by excessive speed, unauthorized incursions into areas of track where maintenance is taking place, and train movement through a mainline switch in the wrong position.

In 2008, Congress mandated that all Class 1 railroad mainlines in the US, such as those used for scheduled passenger service, be equipped with PTC by December 31, 2015. That deadline was later pushed back to the end of 2018 with the possibility of an additional two-year extension.

Incredibly, FRA data shows that through the second quarter of 2017 only 23% of passenger rails in the US had operational PTC and only 41% of passenger locomotives had functional PTC technology.