When is it acceptable to overtake on the left?

Overtaking on the left is generally acceptable on a one-way road because there are no opposing vehicles that could create a hazardous situation. In a one-way street, all traffic is moving in the same direction, so overtaking left allows for smooth traffic flow without the risk of encountering oncoming vehicles. This practice helps maintain safe distances between vehicles and ensures that drivers can maneuver safely without the added complexities that would exist on roads with traffic coming from multiple directions.

In contrast, the other scenarios where overtaking on the left is suggested do not necessarily adhere to safe driving practices or legal standards. Slowing vehicles could indicate that they may be changing lanes or turning, making overtaking risky. On all types of roads, overtaking on the left may not be permissible due to varying traffic laws and potential dangers associated with oncoming traffic. Additionally, night-time driving adds another layer of complexity related to visibility and reaction time, making overtaking on the left again less safe than on a one-way road where conditions are more controlled.