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Radar and Laser Guns


Police use two types of technology, Radar Guns and Laser Guns, to Identify Speeding Drivers and Issue Traffic Tickets

Picture this:  You’re driving along, focused on the endless to-do list you carry around in your head, mentally checking off tasks completed and trying to schedule those that slipped through the cracks of your busy day.  All of a sudden you whiz past a parked cop pointing his laser or radar gun at passing vehicles. You brake fast, but not so quickly that you call attention to the fact that you might be a few miles over the posted speed limit.

This scenario ends one of two ways. Hopefully, you see no movement from the squad car and you continue merrily on your way. You breathe a sigh of relief and make a mental note to pay better attention to your speed. Or, as you nervously check the rearview mirror, you see the police car make an abrupt turn into the flow of traffic. Flashing lights appear and blaring sirens sound. You’re caught. You’re getting a ticket.

The officer knows how fast you were going. After all, he has technology on his side. You start berating yourself, the entire justice system, and all those things weighing on your mind that distracted you from your speedometer. It’s not a fair fight, you think, as you scan for a place to pull over safely to the side of the road.  While it’s tempting to blow off steam by cursing the advantages police have in determining your speed, it’s more helpful to understand the technology they are using.


Cops Use Two Types of Devices to Determine if Vehicles are Violating the Speed Limit

Radar Guns use normal radar technology. The gun will emit a radio pulse and wait for the reflection. Then it measures the Doppler shift in the signal and uses the shift to determine the speed.


Laser speed guns use a more direct method. They rely on the reflection time of light rather than on the Doppler shift. The gun measures the total time it takes light to reach a car and reflect back. It’s a straight forward process; a laser speed gun shoots a short burst of infrared laser light and then waits for that light to reflect off the vehicle. The gun counts the number of nanoseconds it takes for the round trip, divides that number by 2, and determines the distance to the car. It can then compare the change in distance between the samples and calculate the speed of the car. By taking several hundred samples over less than half of a second, the accuracy can be very high.


For the police, the advantage of a laser speed gun is the ability of the gun to target a specific vehicle. The disadvantage is that the officer has to aim a laser speed gun, whereas, normal police radar with a broad radar beam can measure the Doppler shift without aiming.


Once you are Caught Violating the Speed Laws, What Do You Do When Issued a Speeding Ticket?


Between fines, increased insurance premiums and a marred driving record, a minor speed infraction is anything but minor! Further, if you speed too many miles above the posted limit, you can even find yourself facing criminal charges. Your best bet to protect your right to drive and avoid expensive fines and insurance premiums, is to hire an established attorney devoted to fighting for you. Michael D. Sheehan has over a decade of experience of doing just that. He has helped Washington drivers avoid expensive fines, higher insurance premiums, license suspensions, blemished driving records and jail time. Whether your speeding ticket was a few miles over the limit, or has resulted in a charge of reckless driving or negligent driving, Mr. Sheehan is ready to be your experienced advocate in the legal process.

Click here if you have received a traffic infraction:

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