RADAR in Prince William County Speeding Cases

RADAR is an acronym for Radio Detection and Ranging technologies. These devices are detection tools that law enforcement officers use to measure the speed of motor vehicles as they travel past the officer. Part of how this tool measures speed is by evaluating the distance between the targeted vehicle and the RADAR machine.

Prince William County police officers may use hand-held these devices from inside their vehicle or mount them to the outside of their police cars. Mounted detectors are located on either the front of the vehicle or on the rear antennas.

Radar readings can be extremely specific and produce an exact speed that a car is traveling, however, this result may be within a margin of error of at least one or two miles per hour. If a police officer used a speed detection tool to issue you a ticket, consult an experienced speeding ticket attorney who can explain the usage of RADAR in Prince William County speeding cases.

How Does RADAR Work?

Radar beams and waves are used at certain ranges of the radio frequency spectrum to measure the speed at which an object is moving in relation to the RADAR device. This tool emits a continuous signal outward, and then receives the signals once they bounce off of a targeted object. When the signals hit a targeted object, the wave’s original frequency changes to be either higher or lower based on the targeted object’s movement. RADAR then calculates the object’s speed based on this difference in frequency from the originally-emitted signal.

RADAR Device Readings in Court

RADAR readings may be given a great amount of weight during Prince William County speeding cases because most courts consider RADAR as the primary method of measuring a vehicle’s speed. Additionally, state law establishes that RADAR readings are presumed to be accurate if an officer has proper paperwork demonstrating that their device has been calibrated within six months of usage.

RADAR devices are designed to be easy to use by those with proper training. Every officer completes the necessary training courses to understand how to use RADAR for traffic enforcement. Officers must also return to the academy for re-training anytime their department adopts a new brand or type of RADAR device to be used in the field.

Proving Proper Calibration

Law enforcement officers use two different metal tuning forks to calibrate their RADAR detectors. When an officer strikes these forks, they vibrate and produce an exact frequency that is the same as the one that a vehicle generates when traveling between 35 and 65 miles per hour.

If the RADAR measures the correct matching frequency when directed at the tuning fork, this confirms that the device is accurate. If a speed detection machine produces an inaccurate reading, the settings and circuitry of the detector can be tweaked so that it is brought into alignment with proper detection.

However, police officers may indirectly calibrate RADAR detectors by comparing the readings they produce when targeting a vehicle moving at a known speed. For example, it is common for law enforcement to calibrate their own vehicle speedometers, and then travel at a fixed speed while operating a RADAR detector to compare the reading it produces with the vehicle’s speedometer. It is important to note that this method of calibration is more questionable, but also less burdensome for police departments.

The Usage of Personal RADAR Detectors

Typically, the law does not permit drivers in Prince William County to have personal radar detectors. Many drivers from other states do not realize that possessing radar detectors is illegal because other surrounding states have not outlawed RADAR detectors. However, it is legal for drivers to have a device that receives radio waves for lawful purposes and at lawful radio wave frequencies which do not interfere with police radar band frequencies.

The benefit of having a RADAR detector is that it can give a driver prior notice that a police radar is in use in the area, and it can produce its own radio waves which interfere with police officer’s RADAR device. Therefore, drivers who habitually speed and want to minimize their risk of getting pulled over could potentially use a personal RADAR detector to break the law without consequences. Using these devices increases the risk of receiving additional charges if a law enforcement officer discovers the device during a traffic stop.

The presence of a RADAR detector in a vehicle provides a legal presumption that the driver is guilty, regardless of intent and whether the detector appears to be in operation. The only defense under the law for having a RADAR detector is when the machine had no power source and was not readily accessible for the driver or any passenger at the time of the alleged offense.

Contact an Attorney to Discuss the Usage of RADAR in Speeding Cases in Prince William County

If you have been issued a speeding ticket, speak with an attorney for help. A legal professional could discuss the usage of RADAR in Prince William County speeding cases and how to build a proper defense if the arresting officer used one of these devices. To learn what an attorney could do for your case, call today.