What is likely a primary consequence of a train derailment?

The primary consequence of a train derailment is unexpected delays and potential injuries. When a train derails, it disrupts the normal operation of rail services, leading to significant delays in schedules for not only the derailed train but potentially for other trains on the same line as well. Additionally, derailments often pose serious risks to the safety of passengers and crew, resulting in injuries or even fatalities in severe cases.

In contrast, the other options do not align with the typical outcomes of a derailment. Increased train schedules or improved infrastructure would be unlikely in the aftermath of a derailment, as resources and focus would shift towards managing the incident and restoring service, rather than enhancing it. Similarly, a reduction in maintenance costs would not logically follow a derailment; rather, it often leads to increased scrutiny of maintenance practices and potentially higher costs associated with repairs and safety investigations.