To drive safely, it is essential that the **driver uses the rearview mirror in a timely manner**. This is because the driver's physical and psychological state, as well as their ability to react to unforeseen events, are crucial for road safety.

- **Reaction to unforeseen events:** A driver must be attentive to what is happening around them, and the proper use of the rearview mirror allows them to anticipate situations and react in time. This is part of the necessary training to drive a vehicle safely.

- **Vehicle conditions:** Although the fragments do not directly mention rearview mirrors, they highlight the importance of being in good physical and psychological condition to drive. This includes being alert and using all the vehicle's devices, such as mirrors, to maintain safety.

Therefore, using the rearview mirror in a timely manner is an essential practice to ensure safe driving and prevent accidents.