If an officer is pursuing a vehicle, what is the only legal way to signal the car to stop?

The legal way for an officer to signal a vehicle to stop during a pursuit involves using flashing lights. This method serves multiple purposes: it is a clear visual indication that a vehicle should pull over and stop, and it is a universally recognized signal for compliance with law enforcement instruction. Flashing lights alert not only the driver of the vehicle being pursued but also other road users about the ongoing police action, enhancing safety on the road.

Using only a siren may not be sufficient on its own to ensure that the driver is aware of the instructions to stop, as auditory signals may not be heard over loud music or noise and may not effectively convey the urgency of the situation. Similarly, sounding the horn is not a standard or widely accepted signal for a stop and lacks the formality and recognition that lights provide. Following closely does not constitute a lawful order to stop; it may even lead to dangerous situations without making it clear to the driver that they need to yield.