In what situation should you consider a broken impedance bond as safe?

Considering a broken impedance bond as safe under no circumstances is correct because impedance bonds are critical for the proper functioning of signal systems and for the safety of train operations. A broken impedance bond can lead to failures in detecting trains on the tracks, which may result in unsafe conditions such as signal malfunctions or improper track occupancy indications.

The failure of an impedance bond compromises the electrical circuit used for detecting train presence, posing significant risks. Therefore, it is crucial to treat any broken impedance bond with the utmost seriousness, ensuring that appropriate protocols are followed for repair and verification before assuming safety. This principle is vital for maintaining operational safety and integrity within the transportation system.