When is it illegal to pass another vehicle?

It is illegal to pass another vehicle when approaching a hill or curve because visibility is typically limited in these situations. Passing on a hill or curve can create dangerous conditions as oncoming vehicles may not be visible until they are very close, increasing the risk of a collision. The law is designed to ensure the safety of all road users by preventing maneuvers that could lead to accidents in areas where it is difficult to see what is ahead. This is a common traffic rule aimed at maintaining safe driving practices and protecting both drivers and pedestrians.

In contrast, passing is often legal under clearer conditions where visibility allows for safe maneuvers, such as on straight roads or when there are no obstructions. Additionally, passing on a one-way street or during certain speed limits does not inherently make the action illegal; it is the visibility and road conditions that primarily dictate the legality of passing.