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Service Updates and Alerts

How can PTC delay a train?

What do we mean when we say a train is delayed by PTC issues?

Most Metra riders are aware that all railroads, including Metra, are required by federal law to install and implement Positive Train Control (PTC) by the end of 2020. Metra and its freight partners, particularly the BNSF Railway and the Union Pacific, are currently in the midst of rolling out PTC across our rail lines to meet the federal deadline.

PTC is a GPS-based safety technology system that monitors a train’s movements in real-time and will stop a train to prevent train-to-train collisions, over-speed derailments, and unauthorized train movements through work zones or any other restricted section of track. For a video explaining PTC, click here. Trains across the Metra system are now operating with PTC, and as a result, PTC is now being cited in our service alerts as a cause of some delays.

How can PTC delay a train?

In general there are four types of issues that could cause a PTC delay. They are: software, hardware, wayside communications and human error.

Software issues have been a common cause of Metra’s PTC-related delays. It can be as simple as a message conflict during the initialization process before a train run. The software that runs PTC is extremely complex and must be adapted to every unique aspect of our railroad. Metra lines where PTC is operating are either in operating demonstration or testing modes and fine-tuning the software is part of this process.

Hardware issues are self-explanatory and occur if one of the numerous components of the PTC onboard computer system fails.

The wayside communications system monitors railroad track signals, switches, and track circuits and communicates the alignments or indications of track equipment to the onboard system to allow a train to move through a section of track. A failure in this communication link will stop a train because the PTC system is not receiving this data.

Human error issues have also been a common cause of Metra’s PTC-related delays. This type of error has occurred across the rail industry as PTC has been implemented, but the number of human errors have been shown to decline quickly as users gain experience and familiarity with the system. Human error issues can range from mistyping data during the train’s initialization process to the engineer disregarding or not responding quickly enough the PTC system’s instructions. In the second example, the PTC system is functioning as designed when it stops the train.

A PTC issue sometimes requires that the engineer reset the onboard equipment, and that can require about 10 minutes to complete. PTC’s initialization requirements are the primary reason that we’ve been modifying schedules on train lines to increase the time between a set of equipment’s next run and allow for PTC initialization.

As Metra and its freight partners continue to roll out PTC on all 11 lines, Metra expects to need to fix software issues as PTC moves from a test environment to real world application. However, we also expect these needs to decline as the system and the technology mature.

 

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