Pacing is the simplest way of measuring speed. The police officer simply keeps pace with the target car. The officer then testifies that he was keeping a steady distance from target car and what the speed on his own speedometer was at the time.
What many drivers do not understand is that an officer can pace a target car that is in front, to the side, or behind a police cruiser. Some officers will even pace a car that is on a highway from a parallel access road. Typically, the officer tailgates the target car either directly behind or one lane to the right of the back bumper.
Sometimes, when a car pulls up behind a police cruiser, the officer will gradually speed up to see how fast the driver is willing to go. After baiting the driver into speeding, the officer will pull the driver over.
In order to use pacing in court, a police officer must have had the cruiser’s speedometer calibrated recently (usually no more than six months before the date of the offense). Speedometer calibrations are done either by testing the cruiser’s speedometer against a dashboard mounted Radar unit’s ground speed measurements or by using a dynamometer.
Common pacing errors come from the officer not pacing for a sufficient amount of time, speeding up to catch up with a target vehicle but not decelerating completely prior to beginning the pace, attempting to pace a car that is accelerating or decelerating, attempting to pace a car that is changing lanes or separated by other traffic, or pacing from too far away. Once again, a proper tracking history is essential for an officer to avoid pacing errors.
If pacing in a different lane than the target vehicle, an officer cannot will not be able to get an accurate reading on a curve. The cruiser will need to be going faster than the target car if it is on the outside of a curve or drive slower if it is on the inside. A driver should contact a reckless driving attorney immediately if paced on a curve by an officer not directly behind the car.