The following is a release from Metro North:
The delays you experienced this morning were the result of the impact of the extremely cold temperatures on our tracks and signal system.
Steel rail is affected by extreme hot or cold weather. In the severe cold, rail becomes brittle and contracts. This morning, the frigid temperatures resulted in broken rail at several locations.
This not only forced us to take sections of track out of service, but also impacted the circuits of our signal system. To ensure the safe operation of trains, we had to operate at reduced speeds.
The cold weather also resulted in several switch failures, adding to the congestion and delays.
We regret any inconvenience you may have experienced as a result of these weather-related problems.