When must you signal when changing lanes?

Signaling when changing lanes is an important aspect of safe driving, and indicating your intentions gives other drivers the necessary warning to adjust their driving accordingly. The correct answer indicates that you should signal at least 100 feet before changing lanes. This distance provides sufficient time for other drivers to notice your signal and react to your movements, promoting safer driving conditions and reducing the likelihood of collisions.

The requirement to signal at least 100 feet prior to a lane change is practical because it ensures that your intentions are communicated well in advance. This is particularly important in situations where other vehicles may not be aware of your presence or your plans to shift lanes. By adhering to this practice, you help to ensure that you and other road users can navigate safely and without unexpected surprises.

In contrast, other choices suggest distances or conditions that do not provide the same level of safety. For example, signaling only when pedestrians are present would neglect the need for clear communication with other drivers. Similarly, signaling only when merging onto a highway implies a narrower focus that doesn't encompass all the necessary situations where signaling is crucial. Finally, signaling at least 50 feet before the turn is not sufficient in many scenarios, as it doesn't give enough time for other vehicles to respond appropriately.