Movement directed by hand signals must be stopped if there is:

• A. There is doubt for whom the signal was intended
• B. The signal is not visible
• C. There is doubt concerning the meaning of a signal
• D. The signal is from an unauthorized person

Answer: (C)

Hand signals directing movement must be clear and understood by everyone involved. If there is doubt concerning the meaning of a signal, you must stop the movement and get a definite, understood instruction before proceeding. This prevents acting on an incorrect or ambiguous instruction, which could lead to a dangerous situation on the track. If the signal isn’t visible or comes from an unauthorized person, you should also stop and reassess, but the key rule being tested is to halt when the meaning of the signal is in doubt so safety isn’t compromised.