When are you allowed to pass on the right?

Passing on the right is permissible when driving on a one-way street or highway marked for multiple lanes. This rule acknowledges that in such environments, vehicles can safely overtake others without crossing into oncoming traffic, which is a significant hazard. A one-way street or highway configured with multiple lanes allows for smoother traffic flow and provides the necessary space for a vehicle to maneuver safely around slower-moving traffic.

In other circumstances, like on roads with a double solid line, passing on the right is not allowed as it often indicates that both directions face restrictions on passing for safety reasons. Additionally, passing due to another vehicle signaling doesn't conform to a rule that specifically allows passing in that scenario; it's better to pass only when conditions are safe and legal. Lastly, passing when traffic is moving slowly isn't a standard justification on its own, as safe passing depends on the road type and visibility rather than just traffic speed.