Under what condition may a driver pass another vehicle on the right?

Passing another vehicle on the right is permissible when that vehicle is making or about to make a left turn. This situation creates a scenario where the left lane is occupied due to the vehicle's intention to turn left, and the right lane becomes a clear and safe passage for the driver wishing to pass. It is essential for drivers to ensure that they have enough space and that the maneuver can be performed safely without risking collisions with other vehicles or pedestrians.

In contrast, while speed limits and road conditions might affect maneuverability, they do not specifically justify passing on the right as clearly as the left-turn scenario does. For instance, a vehicle driving slower than the speed limit may not indicate any reason for the driver behind it to pass unless there is a left turn signal. Similarly, a road being "clear" does not automatically mean that passing is safe, as it depends heavily on the actions of the vehicles involved. Lastly, the act of signaling a right turn indicates an intention to change direction, not necessarily an authorization for other vehicles to pass.