To turn left, it is important to keep in mind that it is **prohibited to do so when there is insufficient visibility**. This is because in situations such as **sharp curves, hill crests, dense fog, or heavy rain**, visibility is considerably reduced, which increases the risk of accidents. In these conditions, it is not possible to clearly see if vehicles are coming from the opposite direction or if there are obstacles on the road, making the turn dangerous.

Additionally, in places such as **tunnels, level crossings, highways, and expressways**, it is also prohibited to change direction unless there are specifically designated areas for it. The lack of visibility in these places can be an additional factor contributing to the prohibition.

Therefore, whenever visibility is insufficient, it is better to wait for conditions to improve before attempting to turn left. This ensures the safety of both the driver and other road users.