When is it illegal to pass another vehicle?

Answer: B — When a solid line separates the lanes

Passing another vehicle when a solid line separates the lanes is considered illegal because solid lines indicate that overtaking or passing is prohibited in that area. These lines are placed for safety reasons, typically in zones where visibility is limited or where the road conditions may make it hazardous to change lanes or pass another vehicle. In such situations, it is essential to follow the traffic markings to ensure the safety of all road users. In contrast, passing is allowed on a one-way street since all vehicles are traveling in the same direction, providing more opportunities for safe overtaking. The speed limit being over 60 km/h does not inherently make passing illegal; it depends on other factors, including road markings and conditions. Approaching a traffic light also does not automatically render passing illegal unless specific restrictions or road markings indicate otherwise.