When are drivers required to stop at airport traffic signals?

Answer: C — Whenever the light is red or if otherwise directed by signage

Drivers are required to stop at airport traffic signals whenever the light is red or if otherwise directed by signage because these signals are in place to ensure safety and efficient traffic flow within the airport premises. The red light indicates that vehicles must come to a complete stop, allowing for the safe passage of other vehicles or pedestrians that may be crossing the roadway. Moreover, airport traffic management is critical due to the high volume of both vehicles and pedestrians, thus adhering to posted signs and signals is vital to prevent accidents and ensure compliance with airport regulations. Understanding this aspect helps drivers navigate through busy airport areas more safely and effectively.