Your traffic light is green. An officer who stands in the intersection faces you, holds up one hand with the palm toward you, and gives one long blast on a whistle. What must you do?

Correct answer: Stop and stay stopped until the officer signals you to move

Why

Officers direct traffic at crashes, events and signal failures, where the normal signals may not fit the situation. To tell drivers to go, an officer usually moves a hand and gives several short whistle blasts; at night the officer may use a flashlight. In North Carolina, uniformed firefighters and rescue squad members can also direct traffic at the scene of a fire or a crash, and their directions must be obeyed too.

Verified against North Carolina Driver Handbook · Traffic Officers · p. 90