Fox River Grove Analysis

     Traditionally, error analysis has focused on identifying the cause. However, one basic finding from research is that accidents in complex systems only occur through the concatenation of multiple small factors or failures, each necessary but only jointly sufficient to produce the accident. Often these small failures or vulnerabilities are present in the organization long before a specific incident is triggered. All complex systems contain such latent factors or failures, but only rarely do they combine to create the trajectory for an accident.

A combination of latent failures occurring simultaneously created the conditions for the Fox River Grove accident

• Communication broke down between the railroad and the transportation department.
• Knowledge from near misses was not shared with the bus driver.
• Acoustic features of the bus interfered with the hearing of the bus driver.
• The training received by the driver was inadequate despite her overall expertise.

There was a failure to coordinate preemption of the stoplight.