What is a common sign of a driver under the influence:

A common sign of a driver under the influence is frequent lane changes without signaling. This behavior often indicates a lack of attention and impaired decision-making abilities. A driver who is under the influence may struggle to maintain situational awareness, leading to erratic driving patterns, such as weaving in and out of traffic or making sudden lane changes without the proper signaling that is expected from responsible driving.

In contrast, consistent speed, smooth acceleration, and proper parking typically reflect a driver who is in control and focused on the road. Thus, the behavior observed with frequent lane changes without signaling starkly contrasts with the characteristics of a sober, attentive driver. Recognizing these signs can help other drivers stay safe and potentially identify dangerous situations on the road.