In which situation might a speed measurement device yield a false positive?

In which situation might a speed measurement device yield a false positive?

• A. When there is only one vehicle on the road
• B. When multiple vehicles are present, and the device captures the speed of the wrong vehicle
• C. When the device is out of battery
• D. When the device is used during bad weather

Answer: (B)

A speed measurement device might yield a false positive when multiple vehicles are present, and the device captures the speed of the wrong vehicle. This situation can occur in areas where there is heavy traffic, and the device has difficulty distinguishing between closely spaced vehicles. Factors such as similar speeds, overlapping detection zones, and the angle at which the device is set up can all lead to it identifying the speed of a different vehicle rather than the target vehicle. This misidentification can result in incorrectly logging a speeding violation, which is why proper training and calibration of these devices are crucial for accurate readings.

The other scenarios do not typically result in false positives. For instance, having only one vehicle on the road would not lead to confusion about which vehicle's speed is being measured. A device being out of battery would simply stop functioning rather than provide incorrect readings, and bad weather might affect the accuracy of readings, but it wouldn't generally misidentify the vehicle's speed.