Final answer:
Overloading the train with excess passengers is considered a violation of rules by train operators.
Step-by-step explanation:
Of the following actions of train operators, the one which would be considered a violation of rules is for them to overload the train with excess passengers.
Overloading a train with excess passengers is a safety hazard as it can lead to overcrowding and increased risk of accidents. Train operators are responsible for ensuring the safety and well-being of passengers, and overloading the train goes against this responsibility.
Adhering to the designated speed limits, ensuring proper maintenance of the train, and adhering to the scheduled timetable are all actions that train operators are expected to do as part of their job.