Final answer:
The white square sign with NO TURNS indicates that no turns in any direction are allowed. This sign is essential for traffic safety and flow control.
Step-by-step explanation:
When encountering a traffic sign that states NO TURNS with a white square background and black lettering, it is important to understand the specific traffic rule it communicates. This sign indicates that d) No turns in any direction allowed. This means you are not permitted to make a left turn, right turn, or U-turn at the intersection where this sign is posted. Complying with this sign is crucial for ensuring the safety of motorists and pedestrians alike, as it is typically placed in areas where turns could be hazardous or where traffic flow needs to be strictly controlled. Always observe road signs and follow their instructions to maintain safe driving conditions.