As Metra lines continued to face delays Monday morning across the Chicago area, the commuter rail system issued a statement explaining what led to the disruption.
"The cause is the failure of the PTC system operated by CN, which is affecting all Metra lines that use (Heritage Corridor and North Central Service) or cross (Milwaukee District North and UP Northwest) CN tracks at locations that are controlled by CN," a Metra spokesman wrote in an email to NBC Chicago.
The spokesman explained, "Positive Train Control (PTC) is a system that will automatically stop a train if the engineer fails to obey a signal or exceeds the speed limit."
On Monday the Union Pacific Northwest, Milwaukee North, North Central Service and Heritage Corridor lines were all impacted by signal and train control problems, Metra announced on X, formally known as Twitter. The Milwaukee District West line was delayed due to mechanical failure, according to Metra.
The length of the delays weren’t known, though in its statement at about 9:30 a.m., Metra explained it was "able to get clearance to operate over the junctions" on the Milwaukee North and UP Northwest. "We are waiting for CN’s computer system to come back."
NBC 5 traffic reporter Kye Martin encouraged riders to check the Metra website and the Ventra app for updates.
Read Metra's full statement below:
Local
"The cause is the failure of the PTC system operated by CN, which is affecting all Metra lines that use (Heritage Corridor and North Central Service) or cross (Milwaukee District North and UP Northwest) CN tracks at locations that are controlled by CN.
Positive Train Control (PTC) is a system that will automatically stop a train if the engineer fails to obey a signal or exceeds the speed limit, thereby preventing train-to-train collisions, unauthorized entry into work zones and derailments due to speeding or moving through misaligned track switches. The system integrates GPS, trackside sensors and communications units, onboard computers, and centralized train dispatching systems. Together, these components track trains, convey operating instructions, and monitor the crew’s operation of the train.
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Every railroad is responsible for the PTC system on the tracks they own, and every railroad that operates over another railroad’s tracks must have onboard PTC units that are interoperable with the host railroad’s system. When CN’s PTC system failed, no trains were able to operate on its tracks or cross tracks at intersections it controls.
We were able to get clearance to operate over the junctions about an hour ago on the Milwaukee North and UP Northwest but still aren’t operating on the HC and NCS. We are waiting for CN’s computer system to come back."
