Which scenario would indicate a driver might be under the influence?

A driver weaving in and out of lanes is a significant indicator that they may be under the influence of alcohol or drugs. This behavior suggests a lack of coordination, impaired judgment, and difficulties with spatial awareness, all of which can stem from substance use. A sober driver typically maintains a consistent lane position and displays controlled driving behavior, while erratic lane changes indicate potential impairment.

In contrast, actions like merging skillfully into traffic, driving at a consistent speed, and using turn signals correctly exemplify responsible driving behavior. These actions reflect an awareness of one’s surroundings and adherence to traffic laws, which are typically compromised when a driver is impaired. Observing erratic movement, such as weaving, is a key sign of possible intoxication and warrants further attention.