This is a modern term. One would imagine that the LNWR would use the term SACK in relation to a driver doing this! In 1998 over 630 signals were passed at danger. The vast majority were passed by a few metres and stopped in the overlap. Most were caused by slippery rail conditions affecting braking. Some were caused by signals changing to red a short time before the train approached it because the signal had failed. Signals, like most railway equipment, are designed to fail-safe, and will display a red aspect if they fail. A few, however, were due to drivers failing to observe the red signal.