What does a double yellow line indicate?

A double yellow line indicates that no passing is allowed on either side of the road. This marking is used to separate traffic moving in opposite directions and serves as a clear signal that overtaking another vehicle is prohibited. The presence of the double yellow lines establishes a safety boundary, alerting drivers that the conditions do not permit safe passing because visibility may be limited or the road may be too narrow.

The other options suggest scenarios that do not align with the meaning of a double yellow line. For instance, a situation where passing is allowed would be marked differently, and a lane designated for left turns would typically be indicated with a different lane marking protocol. Furthermore, road construction would usually be indicated by specific signs or cones rather than a double yellow line. Thus, understanding the significance of a double yellow line is crucial for safe driving practices.