What does a solid yellow line on the road signify?

A solid yellow line on the road signifies that passing is not allowed. This marking is used to indicate to drivers that they should not cross the line to overtake another vehicle. The presence of a solid yellow line generally suggests that the visibility or road conditions do not permit safe passing, such as on hills or curves where oncoming traffic may not be visible. It is important for drivers to obey this marking to ensure safety on the road, as failing to do so could result in head-on collisions or other dangerous situations.

In contrast, a dashed yellow line would indicate that passing is permitted when it is safe to do so, while a solid white line signifies that lane changes are discouraged but doesn’t prohibit it. Other options such as lanes for turning or signs indicating school zones are represented by different markings or signage entirely, which do not conflict with the solid yellow line's meaning.