What does a solid yellow line mean?

A solid yellow line indicates that no passing is allowed. This line serves as a warning to drivers that it is not safe to cross over into the opposing lane to overtake another vehicle. The presence of a solid yellow line signifies that there may be hazards such as curves, intersections, or other visibility restrictions, making passing potentially dangerous.

In contrast, dashed yellow lines would indicate that passing is permitted under certain conditions, whereas a solid line indicates the opposite. This is an important safety feature on the roads that helps regulate traffic flow and minimize accidents.