When should you not pass another vehicle?

Not passing another vehicle when a vehicle is approaching is important for safety. This scenario often indicates that oncoming traffic is close enough that attempting to pass could create a dangerous situation. If you were to pass at that moment, you may not have enough time or space to complete the maneuver safely, which could lead to a head-on collision or force the oncoming vehicle to swerve or brake sharply.

In contrast, heavy traffic typically makes passing more difficult but does not inherently create an unsafe condition unless conditions are specifically risky. A marked passing zone indicates it's safe to pass, and a green light means that you have the right of way, allowing you to go forward rather than pass. Therefore, recognizing when to refrain from passing is crucial for maintaining safety on the road, particularly in the face of oncoming vehicles.