The state accident commission already requested in 2024 measures to avoid human errors when the system falls

BarcelonaThe Railway Accident Investigation Commission (CIAF) —since last July the Independent Administrative Authority for Technical Investigation of Railway, Maritime and Civil Aviation Accidents and Incidents (AAIITAI)— had already recommended in a 2024 report to adopt technical measures and reinforce protocols, after pointing out that human verification is "susceptible to failure" in cases where it replaces the automated system, as everything indicates happened in this Wednesday's accident in Urda (Toledo), which has caused at least 69 fatalities.

The report refers to an incident that occurred on June 25, 2024, when the AVE 05903, which was circulating with the ERTMS Level 1 railway safety system, improperly passed a signal that ordered it to stop at Cuenca-Fernando Zóbel. In this case, the initial error was the driver's, in confusing the aspect of the signal, but the traffic manager then committed a second error by authorizing it to continue. The TRIP system (a safety mode of the ERTMS system) automatically stopped the train, but neither the driver nor the traffic manager had identified the improper passing.

The document illustrates the same type of vulnerability that would have been detected in the Urda accident: when automation or signaling fails, safety comes to depend on human authorization, and if a technical automatic restriction is missing, this failure can escalate into a collision. The CIAF underlined in 2024 that in Cuenca the authorization to resume the journey had been based on human verification—checking that the block was clear—and that this barrier was "susceptible to failure," and for this reason, it recommended that technical measures be taken. "This barrier is susceptible to failure, as it depends completely on the human factor, which highlights the need to implement technical mitigating measures," the report states.

In addition, the CIAF, which had already documented a recurrence, recommended reinforcing signal ergonomics, protocols after a TRIP, and the implementation of ERTMS Level 2.