What does a solid double yellow line indicate?

A solid double yellow line on the road indicates that no passing is allowed in either direction. This marking serves as a clear visual cue to drivers that they should not attempt to overtake another vehicle while driving in either lane adjacent to the line. The primary purpose of this rule is to enhance safety on roads where visibility may be limited or where passing could create a hazardous situation.

For instance, solid double yellow lines are often found on two-lane roads where there may be a curve, hill, or other conditions that make passing unsafe. By enforcing a no-passing rule, these lines help to reduce the risk of head-on collisions and other types of accidents that could occur if vehicles were permitted to cross over into oncoming traffic.