What does a double yellow line on the road signify?

A double yellow line on the road signifies that no passing is allowed. This marking is used to indicate that the lane separation is meant to prevent vehicles from crossing over to the opposing traffic lane for overtaking or passing another vehicle. The presence of a double yellow line suggests that the visibility or the road conditions may be unsafe for such maneuvers, thereby prioritizing safety on the road.

In contrast, the other options present various rules or situations that do not align with the meaning of a double yellow line. For instance, passing allowed with caution would be indicated by a single broken yellow line. Road construction zones are typically marked with different signs and markers to inform drivers of hazards ahead, while speed limit zones are indicated with specific speed limit signs rather than line markings on the road itself.