signalfel

From signal (“signal”) +‎ fel (“error, fault”).

signalfel n

1. (railroad) collective term for error signals from the safety system which assess, for yet unknown reason, that the route cannot be operated safely (e.g. a broken light bulb, blocked switch, faulty communication antenna, unknown position of a train, or an open railway barrier)
   • 2020 October 26, headline on svt.se:

     Signalfel orsakar stora förseningar i tunnelbanan

     Signal errors are causing long delays on the subway

Despite what the name might suggest; the word does not refer to a faulty signal, but instead to the signal that indicating that something is wrong.

• nagelfils