What do police officers typically observe to justify a traffic stop after radar/lidar detection?

When police officers detect a vehicle's speed using radar or lidar, they often look for erratic driving behavior or speeding that correlates with the detected speed. This observation is crucial because it provides tangible evidence that the vehicle may be operating outside of legal parameters, justifying a traffic stop.

For example, if an officer uses a radar device and sees a car exceeding the speed limit, the immediate follow-up observation of how that vehicle is behaving on the road—like weaving in and out of lanes, making sudden stops, or showing signs of aggressive driving—helps establish a clear basis for the stop. This combination of technological detection and visual confirmation aligns with law enforcement protocols, ensuring that the stop is supported by direct evidence of potential traffic violations, thereby enhancing public safety.

The other choices do not serve as strong justifications for initiating a traffic stop. License plate registration might provide information about ownership and legality, but it does not indicate any immediate reason to stop a vehicle. Time of day and weather conditions may influence driving behaviors but do not directly justify a stop unless linked to unsafe conduct. Officer's personal observation history might provide context for future stops, but it cannot be the sole basis for justifying a traffic encounter. Thus, observing erratic driving behavior or