What does a solid yellow line at the left of your lane indicate in Ontario?

A solid yellow line at the left of your lane in Ontario indicates that it is unsafe to pass. This line serves as a clear visual cue to drivers that passing is prohibited due to potential hazards that could arise, such as oncoming traffic or reduced visibility. It is designed to enhance safety on the road by discouraging overtaking in areas where it would be dangerous. This rule is part of the traffic regulations to ensure that drivers adhere to safe practices while navigating the roadways.

In contrast, other options imply situations that do not apply to the context of the solid yellow line. For instance, safe passing would be marked by a broken line, while no parking zones are indicated by specific signs. Also, mandatory lane changes are regulated under different circumstances and not indicated by solid lines.