Under which condition is passing another vehicle illegal?

Passing another vehicle is illegal when there is a solid line on your side of the road because solid lines indicate that overtaking is prohibited in that area. The purpose of the solid line is to enhance safety by preventing passing in situations where visibility is limited or where it is unsafe to do so, such as near intersections, curves, or other hazardous conditions. By adhering to this rule, drivers can significantly reduce the risk of head-on collisions and other accidents that can occur when dangerous passing maneuvers are attempted.

The other conditions may have restrictions or considerations, but they do not universally indicate that passing is illegal. For example, approaching a curve may suggest added caution but does not inherently make passing illegal. A learner's permit does not by itself restrict passing; rather, the driver must constantly adhere to safety regulations. Similarly, driving on a one-way street generally allows for passing as long as visibility and safety conditions are met.