Multiple Metra lines impacted by signal issues during morning commute

CHICAGO (CBS) — Multiple Metra lines have been impacted by signal issues during Monday morning's commute. 

Metra reported delays on the Milwaukee District West, Milwaukee District North, Heritage Corridor, North Central Service, and Union Pacific Northwest lines, due to positive train control dispatching issues on tracks owned by Canadian National Railway.

Positive train control systems are designed to automatically stop trains if engineers fail to obey a signal or exceed established speed limits, in order to avoid train collisions and derailments.

The Federal Railroad Administration requires positive train control on all passenger and freight trains in the United States. 

Canadian National released the following statement: 

"CN is aware of an IT issue impacting its train dispatching system in the US. The Company is working to fix the system and get trains moving again quickly and safely. We apologize for the impact and inconvenience this is having on commuters and members of the public."

Some trains were not operating around 7 a.m., and some trains were running 15 to 20 minutes behind. Extensive delays are expected. 

Commuters are advised to check train schedules before heading out. 

This is a developing story.