What does a solid double yellow line indicate about passing?

A solid double yellow line indicates that no passing is allowed in either direction. This marking is designed to enhance safety by delineating lanes where overtaking or changing lanes would be dangerous due to potential oncoming traffic. It is typically found in areas where visibility is limited, such as near hills or curves, or where turning vehicles might hinder safe passing.

The regulation against passing in the presence of solid double lines serves to prevent collisions by ensuring that vehicles remain in their designated lanes without the uncertainty that passing entails. When drivers see this marking, it is a clear signal that they should remain in their lane and exercise caution. Thus, adhering to this rule is critical for maintaining safety on the road.