Biblioteca

The primary function of alternating yellow lights is to warn drivers of a dangerous situation or a special obligation, advising them to drive with particular caution and increased attention to the location. The option referring to imposing a stop is incorrect because these yellow lights do not require vehicles to stop; they serve only as a warning. Stopping would only be mandatory in the presence of a red traffic light. The option referring to the approach of a level crossing is also incorrect, as this situation is signaled by specific danger road markings and vertical signs, and not by this set of lights associated with speed control.