Keep This On Your Radar

Know Your Rights: Police RADAR Isn’t Always Spot On: Contesting Your Traffic Citations in Court

What happens if you’re sure you weren’t speeding but the cop that pulled you over said you were? First ask yourself: Are you certain you weren’t being a bit generous with the gas pedal? Police radar relies on a scientific and proven method of evaluating vehicle speed. That said, it isn’t always right.

A number of factors can contribute to police radar giving incorrect results. Most involve human error where the reading on the device is misinterpreted and the officer fails to even realize it.

One of the most common problems relates to other traffic on the roadway. Other traffic can effectively create “noise” that creates false readings. If radar is bouncing off other vehicles in addition to yours, the speed reading can result in a measurement that compares two vehicles’ speeds to each other instead of measuring the speed of your vehicle as it travels over the roadway.

Another type of error is referred to as the “cosine effect”. This basically refers to the angle at which a speed reading is made, and which can produce error. The most accurate measurements are made when the vehicle being measured is coming directly towards or going directly away from the radar and at an angle as small as possible. As the angle increases, the accuracy of the speed reading is reduced. The speed reading can actually show a LOWER than actual vehicle speed. This might seem favorable at first, but next the radar device tries to compensate for the angle by adding speed. Unfortunately, if the radar device is set up incorrectly, or the officer attempts a reading at a large angle, the compensation of the machine may produce a speed reading that is wildly inaccurate, and mostly likely not in the motorist’s favor.

Police radar isn’t exactly rocket science but errors can easily be made that misrepresent true vehicle speed. If you feel your vehicle speed was misrepresented by a police officer and you think there are circumstances that may have contributed to an inaccurate speed reading, you should contact my office.

Fred Antenberg is an Traffic Attorney in Columbia, Maryland that handles criminal defense matters including traffic cases in Howard County, Maryland, and surrounding counties. CONTACT Fred for your FREE CONSULTATION at 410-730-4404.