What may happen if a driver's BAC is below the legal limit but shows signs of impairment?

When a driver's blood alcohol concentration (BAC) is below the legal limit, it might lead some to assume that they are not violating any laws. However, law enforcement officers are trained to observe signs of impairment that can arise due to alcohol consumption, even at lower levels. If a driver exhibits behavior indicative of impaired functioning—such as poor coordination, difficulty speaking, or judgment issues—they may still be deemed unsafe to operate a vehicle.

In such cases, officers have the discretion to arrest the driver for driving while intoxicated (DWI) despite a BAC reading that falls below the legal threshold. This is grounded in the overarching principle that operating a vehicle safely is priority, and impairment, regardless of the BAC level, poses a risk to both the driver and others on the road. The decision to arrest is based on the driver's overall observed state rather than just the numerical evidence of alcohol consumption.