To assess the speed of a moving vehicle, police officers typically use a radar gun. Although officers are trained to determine speed visually, radar remains the most accurate way to catch speeders. But is radar really as on-the-nose as it’s made out to be? Not necessarily. Here’s why. 

Angles Matter! 

What angle the police radar gun is in relation to your moving vehicle significantly impacts the accuracy of the readout — this is called doppler shift, and for a radar reading to be accurate, the gun must have been at an angle of 11 degrees or less. If the angle is greater than 11 degrees, the reading will not be accurate. Which type of radar the officer was using determines whether the inaccuracy is in your favor or the officer’s.  

The Accuracy of Stationary Radar 

If your vehicle approaches the police officer at an angle and you maintain the same speed, the relative speed of your vehicle measured initially will be the most accurate. As you continue to approach the officer and your angle increases, the speed measured by the radar gun decreases, even if your actual speed does not. This error is in your favor, since the radar gun will display a speed lower than your actual speed.

The Accuracy of Moving Radar 

Moving radar is a little more difficult to assess whose favor the inaccuracy skews towards. Moving radar measures the speed of approaching vehicles while an officer is driving by capturing both the speed of the officer’s vehicle and the speed of the vehicle approaching the officer when both are moving. If the angle is 11 degrees or less, the radar gun will accurately calculate the approaching vehicle’s speed. If the angle is greater than 11 degrees, the radar gun cannot accurately calculate the speed of the approaching vehicle, and it’s completely variable whose favor the error will be in — yours or the officer’s. 

Were You Issued a Speeding Ticket? It May Have Been in Error 

If you were issued a speeding ticket and the officer who stopped you measured your speed at an angle greater than 11 degrees — moving or stationary — chances are, the reading was inaccurate. Contact an experienced Atlanta traffic ticket lawyer to fight the ticket and prevent points being added to your license. Contact the Kimbrel Law Firm for legal help by calling (770) 349-9219. We’re available now to assist you.