What type of trains does an advisory speed sign with a blue background and yellow writing apply to?

An advisory speed sign with a blue background and yellow writing specifically applies to freight trains exceeding 1150 meters. This type of signage is designed to communicate safe speed limits to longer freight trains, which may have different dynamics and handling characteristics compared to shorter trains. Longer freight trains can require more stopping distance and have different handling performance, particularly when negotiating curves or gradients.

This differentiation is crucial for maintaining safety and operational efficiency on the tracks, allowing for tailored speed regulations that consider the unique needs of longer freight operations. By specifying this sign for freight trains over a certain length, it helps ensure that the crew operates within safe limits, reducing the risk of incidents related to excessive speed or difficulty in control.