During the 3 DUI phases, what is evaluated in the 'Vehicle in Motion' phase?

The 'Vehicle in Motion' phase of DUI evaluation specifically focuses on observing the operation of the vehicle as it moves. This phase is critical for identifying potential indicators of impaired driving behavior. Evaluators pay attention to the vehicle's speed, braking patterns, and overall control. If a driver is showing erratic speed, such as driving too fast or too slow, or if there are issues with how the vehicle brakes, these are strong signs that the driver may be impaired.

This phase is conducted before any interaction with the driver, so factors such as driver's identification, passenger behavior, or vehicle registration are not the primary concerns during this observation. The emphasis is firmly placed on the driving behavior itself, which directly relates to the ability to operate a vehicle safely. Observations made during this phase are often used as justification for stopping the vehicle and initiating further evaluation, making the assessment of speed and braking problems essential for determining potential DUI offenses.