What action should be taken when the entire train has passed the Resume Speed Sign?

When the entire train has passed the Resume Speed Sign, the appropriate action is to proceed at the speed posted on the Approach Speed Limit Sign. This action ensures that the train is adhering to the established speed restrictions that are in place for safety and operational efficiency.

The Resume Speed Sign indicates that the train can start increasing its speed after complying with any preceding restrictions. However, it's crucial to follow the guidelines established by the Approach Speed Limit Sign, which may impose a specific speed based on track conditions, curves, crossings, or other operational factors. Therefore, maintaining the posted speed limit helps to ensure safe operations, as it considers the train's momentum, the physical characteristics of the environment, and any potential hazards that may still be relevant even after passing the Resume Speed Sign.

In contrast, immediately resuming maximum speed could lead to unsafe situations if the track conditions or other factors do not support such speeds. Maintaining the current speed until further notice could also be unsafe if the train needs to accelerate based on the upcoming conditions. Stopping and awaiting instructions may be unnecessary and could disrupt operations unless expressly required by specific signals or circumstances. Following the posted speed on the Approach Speed Limit Sign is a balanced, safety-oriented approach that ensures compliance with operational protocols.