Which of the following is a sign of impaired driving?

Sudden lane changes without signaling is a classic indication of impaired driving behavior. When a driver is under the influence of alcohol, drugs, or other impairments, their ability to process information and react may become compromised. This can lead to erratic driving patterns, such as making unanticipated lane changes. A driver who is alert and in full control typically exhibits consistent behavior on the road, which includes signaling before changing lanes to communicate their intentions to other road users. Such sudden and unpredictable movements not only increase the risk of accidents but also highlight a lack of attention and impaired judgment, both of which are hallmark signs of someone who may be driving under the influence.

In contrast, consistent speed within the limit and frequent stops at traffic lights generally suggest a driver who is attentive and following traffic laws, while driving with headlights on during the day may just indicate adherence to safe driving practices in certain conditions rather than impairment.