For motorcycles traveling at **more than 100 kilometers per hour**, it is mandatory to have **two rearview mirrors**, one on each side of the vehicle. This is because at higher speeds, it is crucial to have a **clear and complete view** of what is happening behind and to the sides of the motorcycle to ensure the safety of the driver and other road users.

- **Left mirror**: Allows the driver to see traffic approaching from behind on the left side.
- **Right mirror**: Provides visibility of traffic approaching from the right side.

This safety measure is especially important for motorcycles, as they are more **fragile and less visible** than other vehicles, which increases the risk of accidents. Therefore, having both rearview mirrors helps reduce this risk by improving the driver's visibility.