How often should safety checks be performed on a train?

Daily or before each journey is the correct answer because safety checks are critical in ensuring the reliability and safety of train operations. Conducting these checks routinely helps to identify and rectify any potential issues that may arise from operational wear and tear, environmental factors, or mechanical failures. Regular inspections ensure that all safety systems are functioning correctly and that the train is in a fit condition to operate, thereby minimizing the risk of accidents or service disruptions.

While other answer choices suggest different frequencies for safety checks, they do not align with the best practices within the railroad industry, which emphasize vigilance and proactive measures. Safety checks that occur only when issues arise or on a less frequent basis, like weekly or monthly, might lead to undetected problems compounding over time, which could jeopardize the safety of passengers and crew. Thus, the practice of conducting checks daily or before each journey is essential for maintaining high safety standards in train operations.