What does a solid white line on the road indicate?

A solid white line on the road serves as a clear indicator that overtaking is not permitted. This line is a traffic control measure that aims to enhance safety by discouraging drivers from crossing it to overtake another vehicle. The presence of this line generally signals to drivers that the road conditions may be hazardous for overtaking, such as limited visibility, sharp bends, or other situational dangers that could lead to accidents if overtaking were attempted.

While merging is a common practice in different driving contexts, a solid white line explicitly indicates that merging or changing lanes through that line is not allowed. It's important for drivers to respect this line to maintain road safety and optimal traffic flow. In contrast, options referring to lane boundaries or parking regulations do not relate to the implications of a solid white line, which focuses mainly on preventing overtaking.