In traffic control, two whistle blows indicate which action?

• A. Go
• B. Stop
• C. Yield
• D. Proceed With Caution

Answer: (A)

In traffic control, audible whistle signals are used to coordinate movement quickly and unambiguously. Two quick whistle blasts are the go signal, meaning drivers or pedestrians may proceed through the controlled area or intersection. This distinct two-blast cue is chosen to be clearly different from other signals, like a single whistle, which commonly indicates stop. Signals such as yield or proceed with caution are typically conveyed by signs, hand signals, or verbal instructions rather than a two-blast whistle code. So hearing two quick whistles tells everyone it’s now safe to move forward.