It is not permitted to change direction on a **slope with limited visibility**. This is because in situations where visibility is reduced, such as on curves or crests, it is not possible to clearly see if vehicles are coming from the opposite direction. This makes changing direction dangerous, as it cannot be ensured that the road is free of other vehicles.

Furthermore, on slopes with limited visibility, it is difficult to calculate the distance and speed of approaching vehicles, which increases the risk of accidents. Therefore, to ensure the safety of all road users, it is prohibited to make direction changes under these conditions.