The good, the bad, and the lost: a meta-analysis of rail signal passed at danger incident investigations using AcciMaps and systems thinking

• First aggregate analysis of SPAD incident investigations using AcciMap technique. • Most contributory factors were concentrated at physical processes system levels. • Driver cognitive (dis)engagement was the most frequently cited contributing factor. • Corrective actions reiterated the status quo rather than redesign ineffective controls. • Findings challenge the illusion of system learning in SPAD investigations. Signal Passed at Danger (SPAD) incidents, though infrequent, remain a serious threat to rail safety. While often investigated as discrete operational events, SPADs are symptomatic of deeper system conditions. Investigations tend to follow linear logics of human error and focus corrective actions on individual behaviour—especially that of the train driver. However, such approaches may obscure rather than reveal meaningful system-wide learning. This meta -analysis used the AcciMap technique to analyse and aggregate findings from SPAD investigation reports ( N = 49), offering a unique holistic perspective. A total of 859 contributory factors were identified (∼17 per SPAD), with most (∼62 %) reported to occur at the level of physical processes and actor activities. The largest aggregate contributory factor being attributed to SPADs was driver cognitive (dis)engagement (63 factors). Thematic aggregation revealed four themes: (1) A signal lost in the noise , relating to information overload in the rail environment and inevitable separation of human attention from signals; (2) Lost in translation , highlighting interchangeable and indistinct use of labels and concepts employed during investigation; (3) Lost in the brake down , reflecting a dominant narrative of driver (in)action and wrong-doing; and (4) Lost in the loop , pointing to surface-level corrective actions that repeated what was expected rather than redesign ineffective controls. Findings are discussed by reflecting on the question: “what might SPADs be trying to teach us?” By shifting the analytical lens from individual to system, this study challenges dominant narratives of driver blame and considers whether current investigations genuinely reflect systems thinking or merely perpetuate an illusion of learning.