Jul 03

Jon Zimmerman

Can I Counter RADAR With GPS When Fighting My Speeding Ticket?

by Jon Zimmerman

This was the topic of a recent news story, which did not get the answer quite right. The short answer is generally no, not at this time, and drivers should not go rushing to the stores to buy GPS devices to counter speeding tickets. (The exception would be if you could bring in an expert to testify about the high accuracy of GPS as a speed measuring device - and even then a court in Washington would probably be reluctant to allow such new technology into evidence). Imagine this: you're driving a long, minding your own business, and Officer TicketCop pulls you over and he issues you a speeding ticket. He tells you that your car, according to his RADAR (radio detection and ranging) device, clocked your vehicle traveling 10 miles over the posted speed limit. Simple enough, right? Not exactly. You counter that you have a GPS system, which stated that your vehicle was traveling less than the posted speed. Can you use the GPS measurement to counter the officer's RADAR unit? Not really. The law is not developed for courts to agree on using GPS as a speed measuring device. RADAR, although it has a lot of problems, has been around for a very long time, and used properly, courts will allow a measurement of speed based on RADAR into evidence. But GPS is newer and based on new technology, you argue. Well yes, that's true, but from a court's perspective, you would need an expert on GPS to vouch for GPS's accuracy as a speed measuring device as well as how it is properly used. Assuming you win on that, you would still have to show that GPS is better than RADAR, and that your GPS measurement is more accurate than the Officer TicketCop's RADAR measurement, and that you employed the GPS device correctly. GPS is used for purposes other than speed, whereas a RADAR gun is used to measure vehicle speed (and as a reason for Officer TicketCop to give a lot of traffic infractions). One of the problems with a GPS system is the user - a user would have to show that the user's GPS measurement is accurate based on the way the user employed the system. Likely a user who is also the driver would have a tough time vouching for speed and vouching that the device was being used properly at the same time. Also, while a GPS device may be useful in measuring the distance a car has traveled, and average speed over a long distance (say point Seattle to point Tacoma), there is no indication that GPS will measure one or more speeds accurately over fixed, shorter distances (say 800 feet) in a matter of seconds. If you just received a speeding ticket or any other type of traffic infraction in the State of Washington, call me, I can help.


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