Signals Passed at Danger (SPADs)
A signal passed at danger (SPAD) is a precursor safety occurrence — an event which could, under specific circumstances, lead to an accident such as a collision between trains. The actual risk of collision following a SPAD depends on many factors including whether the signal is equipped with engineering defences which automatically stop a train once it has passed a red signal, whether the train travelled into another section of track and whether that section was occupied.
The national incident classification scheme contains five subcategories of SPAD. The two key subcategories in terms of risk are Driver Misjudged and Completely Missed While Running. However, it is often difficult to determine the exact circumstances of each SPAD. For this reason, these two subcategories are reported as a combined total (together with one other subcategory called Starting Against Signal).
The other principal type of SPAD in the national incident classification scheme is Restored as Train Approaches. These incidents are often referred to as “technical SPADs”. They involve a signal changing from proceed to stop as a train approaches, with insufficient time given to the driver to stop the train. They are of lesser significance in terms of safety risk as the route ahead of the signal will be set for the train.
The graph below displays the latest published data on signals passed at danger in NSW.
