What does a solid yellow line on the road indicate?

A solid yellow line on the road serves as a critical visual indicator for drivers regarding lane usage. Specifically, it signifies that passing is not allowed in that lane. This is often implemented in areas where it is deemed unsafe to pass due to oncoming traffic, visibility issues, or road conditions. The yellow color represents caution and alert drivers to the need for vigilance.

In contrast, options suggesting that passing is allowed or that it indicates a bike lane or speed limit information do not accurately reflect the meaning of a solid yellow line. Understanding the significance of road markings like this is essential for maintaining safety on the road and adhering to traffic regulations.