Are Radar Guns Accurate? How do the Police know How Fast I was Driving?

Speeding tickets are the most common type of traffic violation, with approximately one out of ten drivers getting pulled over every year. About three-quarters of them are ticketed, most of whom don’t bother to fight the ticket. If you are stopped for speeding, and you choose to fight the ticket, you need to first find out how the cop “clocked” your speed. There are several ways that the police monitor speeding, some being more accurate than others.

Ways That The Police Detect Speeders

You may be thinking that you really can’t afford an expensive speeding ticket or more expensive insurance premiums. But before you call an attorney to help you fight your ticket, you need to find out how your speed was measured by the officer. There are several ways that police departments use to measure the speed of vehicles:

• Pacing
• Laser
• Vascar
• Radar

Once you find out how your speed was measured, you can investigate the probability of flaws in the measurement.

Pacing

Pacing, simply, is when a police officer follows you in traffic and duplicates the speed you are traveling, and makes a note of the speed of his own car. In order for pacing to be accurate, the officer must follow you at a constant distance for a reasonable distance. The problem with pacing as a measurement is that often the officer has to speed up to get behind you, then slow down and maintain your speed. Traffic, hills, curves, etc., will also have an effect on pacing.

Laser

One of the newer ways to measure speed is with a laser. They look a lot like a radar gun but use a low-powered laser light beam to track speed. The beam bounces off the speeding car, allowing the laser unit to calculate the speed. Laser readers are more accurate than radar but are not as widely used by police departments.

Vascar

VASCAR is an acronym for Visual Average Speed Computer and Recorder. Many states allow police officers to use this method to record and catch speeders. It works similar to a stopwatch, clocking the speed and distance driven. It requires that an officer input more information than just pulling the trigger on a laser or radar gun, thus, leaving more opportunities for error. Other issues with using VASCAR are in determining the accuracy of the police car odometer and the reaction time of the officer using the device.

Radar

Radar (Radio Detection And Ranging) is perhaps the most commonly used speed detection device used by police departments across the country. It uses radio waves that bounce off a moving vehicle to determine its speed. It is generally reliable and acceptable for use, although there are some variables that can influence the accuracy of the reading.
The most common type of radar is the hand-held model that most people refer to as a gun. Motorcycle cops, as well as those in cars, use this device frequently because of its ease of use and mobility. Police cars are also sometimes equipped with a stationary unit that is mounted on the rear left window facing backward. The officer can read the information on a display on the dash that displays the highest speed during the time your car passes through the beam.

Are Radar Guns Accurate?

If all things are perfect, radar guns are pretty accurate, to within one or two miles of the displayed speed. However, seldom are things perfect. Many things can affect the accuracy of radar guns, which is why it is important for you to know how your speed was calculated.

The Radar Gun Must Be Recently Calibrated

One of the best ways to challenge the accuracy of your speeding ticket is to ask when the radar gun that calculated your speed was last calibrated. If the unit was not calibrated within its set timeframe, or if it was calibrated incorrectly, there may be grounds to challenge the findings.

If There Were Other Speeding Vehicles

Though radar can be an accurate way to check speeds, it is not without drawbacks. Radar guns and stationary units measure speeds by shooting a radio beam. If multiple speeding vehicles were driving in the same area at the same time, it is difficult to determine which speed was being measured.

Nature Can Distort The Readings

Though not frequent, sometimes dust, wind, and even heavy rain can distort the radio beam as it bounces back to the radar unit.

Speeding tickets can be costly, and you can feel the effects for a long time in higher insurance premiums and fines. If you are ticketed for speeding, a lot can ride on if the reading taken was accurate. Though radar generally is an accurate way to measure speed, it does have its drawbacks. Avoid paying unfair fines by contacting a traffic attorney today.