When passing another vehicle, when is it safe to return to the right-hand lane?

The safe moment to return to the right-hand lane after passing another vehicle is when the entire car you just passed is visible in your rearview mirror. This ensures that you have provided sufficient space between your vehicle and the one you have overtaken, reducing the likelihood of an accident or cutting off the passed vehicle as it may still be in motion.

By confirming that you can see the entire vehicle in your mirror, you are making sure that it is at a safe distance behind you, allowing you to merge back into the right lane without encroaching on their space. This practice is essential for maintaining safe driving distances and ensuring the safety of all vehicles on the road.

Other options suggest actions or criteria that do not ensure a clear and safe distance. For example, signaling alone does not indicate whether there is adequate space to return safely. Similarly, assuming a vehicle is safe to pass when it is only in the blind spot does not reflect awareness of proper distances. Last, simply seeing the rear of the passed vehicle does not guarantee it is safe to merge back into the lane.