North Carolina RADAR State Practice Exam

In the context of Moving RADAR, what does the closing speed represent?

1. The difference between two vehicles' speeds

2. The total speed of the patrol car

3. The sum of the patrol car's speed and the target's speed

4. The average speed of nearby vehicles

The correct answer is: The sum of the patrol car's speed and the target's speed

In the context of Moving RADAR, the closing speed is understood as the sum of the speed of the patrol car and the speed of the target vehicle. This is because Moving RADAR measures the relative speed between the officer's vehicle and the target vehicle when both are in motion. When both vehicles are moving towards each other or in the same direction, you calculate the closing speed by adding the speed of the patrol car to the speed of the target vehicle. This provides the effective speed at which the two vehicles are approaching each other, which is crucial for accurate speed enforcement and detection purposes. By measuring the closing speed, law enforcement can determine how fast a vehicle is traveling relative to the stationary observer, even when both vehicles are moving. The other options do not accurately capture this relationship. The difference between two vehicles' speeds would not accurately reflect how close they are getting to each other; the total speed of the patrol car alone is insufficient without considering the target's speed. Lastly, the average speed of nearby vehicles does not pertain to the specific calculation required for determining the relative motion in a speed enforcement context.