What does a yellow line on the road indicate?

A yellow line on the road serves to indicate a no-passing zone, which is a critical aspect of traffic safety. It signifies that drivers are not permitted to cross that line to pass another vehicle. This rule is especially important in areas where visibility is limited or where conditions may be hazardous, such as on curves or hills. The presence of a yellow line helps maintain safe driving by preventing potentially dangerous maneuvers that could lead to head-on collisions or other accidents. Understanding this can help drivers make more informed choices while navigating the roads.