Under what circumstances is it illegal to pass another vehicle?

Passing another vehicle is illegal when approaching a hill or curve where visibility is limited because doing so poses a significant safety risk. On a hill or curve, the driver may not have a clear view of oncoming traffic. This creates a hazardous situation where a driver could inadvertently enter the path of another vehicle, leading to potentially serious collisions.

In these areas, the inability to see ahead not only makes it difficult to judge whether the road is clear but also the speed and distance of approaching vehicles. This is why such regulations are in place—to increase safety for all road users. The other scenarios presented, such as being in school zones, construction zones, or situations with broken lines, have their own specific rules and guidelines, but the primary concern when passing is always visibility and the ability to make safe driving decisions.