When may you legally make a U-turn at a Nevada intersection controlled by a traffic light?

The manual authorizes a U-turn at an intersection on a green light or green arrow, not on a red light after stopping and yielding. This answer borrows the right-on-red rule, which allows a right turn after a complete stop, and stretches that stop-and-yield permission to cover a U-turn against a red signal.

Police direction is not required; a green signal or green arrow with no posted 'No U-turn' sign, made safely and where not otherwise prohibited, is enough under the manual. This answer half-remembers that a peace officer's direction overrides a traffic light and stretches that into a rule requiring an officer's explicit go-ahead for any U-turn.

A clear road alone does not authorize a U-turn on any signal color; the turn still needs a green signal or green arrow, no posted 'No U-turn' sign, and safe conditions with no other prohibition in effect. This answer latches onto the illegal-U-turn condition 'when other vehicles may hit you' and treats a clear road as the whole permission, skipping the signal-color and posted-sign checks the manual also requires.