During an investigation, which behavior could indicate a driver is intoxicated?

An abrupt swerve is recognized as a behavior that might indicate a driver is intoxicated because it suggests a lack of control or impaired judgment, which are common effects of alcohol and drug use. Such erratic movements can demonstrate that the driver may be unable to maintain a straight path or is having difficulty responding to road conditions. This behavior stands out as it often deviates from normal driving patterns, which typically involve smooth and steady lane changes and adherence to traffic signals.

In contrast, immediate stopping, consistent signaling, and a calm demeanor can be characteristics of both sober and intoxicated drivers. While immediate stopping and consistent signaling may indicate cautious driving, they do not necessarily point to intoxication. A calm demeanor is also not indicative of sobriety, as an intoxicated individual can appear calm while still being impaired. Thus, it is the abrupt swerve that effectively signals potential intoxication due to the associated loss of control and impaired coordination.