When driving on a **motorway** and you have just overtaken another vehicle, it is important to return to the **right lane** as soon as possible, provided it is clear and traffic conditions allow. This is due to several reasons:

- **Traffic regulations:** On roads with two or more lanes in the same direction, using the left lane for overtaking is permitted. However, once the overtaking is completed, you must return to the right lane to avoid obstructing the flow of traffic. This is especially important if another vehicle is approaching at a higher speed from behind.

- **Road safety:** Returning to the right lane helps maintain smooth traffic flow and reduces the risk of accidents. Staying in the left lane unnecessarily could force other drivers to make unnecessary maneuvers, such as lane changes or sudden braking.

- **Completion of overtaking:** Once you have overtaken, it is crucial to indicate your intention to return to the right lane using the appropriate lights. This ensures that other drivers are aware of your movements and can adjust their driving accordingly.

In summary, returning to the right lane after overtaking is a safe and efficient practice that facilitates traffic flow and minimizes risks on the motorway.