When is it illegal to pass another vehicle?

Passing another vehicle is illegal in a no-passing zone because these areas are specifically designated to enhance safety. No-passing zones are usually marked with signs indicating that overtaking is prohibited due to potential hazards such as curves, intersections, or other situations where visibility is limited and the risks of an accident increase. The intent of these rules is to prevent crashes that can occur when a driver cannot see oncoming traffic or when road conditions make it unsafe to pass.

In contrast, the absence of other vehicles, signaling your intentions, or having a green light does not inherently affect the legality of passing, as those situations may still not align with safe driving practices or traffic regulations set forth in no-passing zones.