The **high beam** or **main beam** is primarily used on **roads outside towns or cities**. It is especially useful in conditions of **low natural light**, such as during the night or in poorly lit tunnels. However, there are specific situations where its use is mandatory or recommended.

- **Adverse weather conditions**: On dark days with little natural light, it is necessary to turn on the vehicle's lights, including the high beams, to improve visibility and safety on the road. This is crucial to see and be seen by other drivers.

- **Prohibitions**: High beams should not be used within towns and cities, nor when the vehicle is stationary, to avoid dazzling other drivers.


Therefore, in **adverse weather conditions** on interurban roads, it is appropriate and necessary to use high beams to ensure safe driving.