Learn German: Das Warnsignal beachten und zurückbleiben! - Mind the warning signal and stand back!

In German, the infinitive is often used for impersonal commands. You will see this mostly on public signs, in instruction manuals, or in recipes. It is directed at the general public rather than a specific person.

Why is das Warnsignal placed before the verb beachten?

Because these impersonal commands use the infinitive form, they follow standard infinitive phrase word order. In an infinitive phrase, the verb always goes at the very end, meaning the object (das Warnsignal) must come before it.

zurückbleiben is a separable verb. Why isn't the prefix zurück- separated here?

Separable verbs only split when they are conjugated and placed in the main verb position (like in standard statements or regular direct commands). Since this sentence uses the raw infinitive to form the command, the verb remains completely intact.

Could I say this out loud to someone who is standing too close to the train tracks?

Usually, no. Infinitive commands are almost exclusively written (like on automated signs at a train station) or played over pre-recorded loudspeaker announcements. If you were speaking directly to a person, you would use a regular imperative form like Bleiben Sie zurück!