What should a driver do immediately after noticing a stop signal?

When a driver notices a stop signal, the first and most crucial action is to stop and implement emergency procedures. This is vital for several reasons.

Firstly, a stop signal indicates that there is a critical need to halt operations—this could be due to an obstruction on the tracks, a hazardous situation, or the presence of another train. By stopping immediately, the driver ensures the safety of everyone involved, including the crew, passengers, and nearby individuals.

Secondly, after stopping, the driver can adequately assess the situation. Implementing emergency procedures allows the engineer to follow established protocols for communicating with dispatch or following signal rules. This structured response is essential in maintaining safety and operational integrity.

Other actions, such as checking speed before passing the signal or taking no action if safety is perceived, could lead to dangerous consequences. Slowing down and assessing the situation, while better than ignoring the signal, still does not provide the immediate safety response required in the presence of a stop signal. Therefore, stopping and executing emergency procedures is the correct and most responsible action to take.