QuestionHey Paul,
My wife was pulled over this morning and was given a ticket for going 64 in a 45 MPH area. The ploiceman that clocked her was only 1/4 of a mile away from where she pulled out of another street so she would have had to be really hammer down to have reached 64 by the time she made it to where he was sitting clocking traffic. Also there was a van that went past her and we are both thinking that he tagged her with a ticket on the wrong vehicle that was speeding. Can you tell me how radar works or rather how an officer knows he has the correct vehicle when clocking traffic?
Needless to say she is going to take off of work to go to court to protest this ticket and we're hoping it is either thrown out or reduced siginificantly since she was only going approximately 35 MPH. This will most likely be a high priced ticket at the MPH the officer says she was over the limit. Lastly, if you have any advice on fighting a ticket that would be appreciated as well.
Thank you for taking time to answer my email.
Brian Stephens
AnswerDear Brian,
There are basically two types of speed detector, Radar and Laser.
A Radar detector uses a principle called Doppler shift. This is the same principle that makes a passing train/motorbike etc sound higher in pitch when it is moving toward you than when it is moving away from you. The radar sends out a radio signal towards the vehicle. When the signal hits the vehicle some of the signal is bounced back. If the vehicle wasn't moving the returned signal would be the same frequency as the one send, but if if was moving the returned signal has a changed frequency. The detector uses the frequency of the returned signal to determine the speed.
A Laser detector works on a different principle. It sends out a pulse of laser light and measures the time it takes to travel from the detector to the vehicle and back. It then half's this time and times it by the speed of light to work out how far the vehicle is away. By doing this repeatedly (about 1000 times a second) it can work out the difference in positions every time it takes a reading and therefore work out the speed of the vehicle very accurately.
There are advantages and disadvantages to both systems. A laser detector is very accurate as the cone of light that leaves the gun is only 3 feet wide when it is 1000 feet away which allows the officer to target specific vehicles. The problem is the officer must aim at the vehicle to get the reading. The advantage with the radar detector is that the officer doesn't have to aim as accurately as the cone of the radio waves is much larger.
It is my understanding of the radar type that the unit always returns the speed of the strongest bounced signal. So that if there was a truck (or van) behind you, although it was further away it is quite possible that it returned a stronger signal, and the officer picked up the reflection from this vehicle rather than of your wife's, even if he vas pointing the gun directly at your car.
So your defence depends mainly on what type of detector the officer was using. If you are sure you were not speeding it is more than likely that the officer had a radar type detector in which case it would be quite easy to say that the officer picked up the wrong vehicle as radar would pick up the van as it had a lot more parts facing the detector (a car only has the front bumper visible as any other surface would reflect the signal in directions away from the detector). If the officer had a laser gun then they must have been pointing at the wrong vehicle, which is much less likely and harder to defend.
For more information on how detectors work you can visit these web pages
Radar Dector >>> http://auto.howstuffworks.com/radar-detector1.htm
Laser Detector >>> http://auto.howstuffworks.com/question396.htm
I am from the United Kingdom so am not experienced with the US legal system. (I know you are not from the UK as we don't have 45mph speed limits, just limits in multiples of 10), but from what I have read on the internet, if the officer doesn't appear in court to give evidence then the case is usually dropped. So just turning up for court may give you a chance to beat the ticket.
Before going to court request from the police department copies of the manufactures names, models and serial numbers of the speed detector used in your case, Copies of the manufactures recommended maintenance schedule, any literature about aiming, weather and traffic limitations for the type of detector used. A copy of the past six months maintenance record for the detector used. A copy of the officers Authorised Certification Of Training on the proper use of the speed detector used, and a copy of the patrol car assignments for the date you got the ticket. Find out all you can on the particular model used from the manufacturer (either on the internet of in writing)
Be warned that asking for this information can work for you or just want them want to nail you more. As I said I am not a legal expert or from the US and my advice in this matter shouldn't be taken as professional legal advice, but just as my personal thoughts on the matter. (So please don't sue me if the advice makes your case turn out worse than just paying the ticket)
For information on beating a traffic ticket try this web site
http://www.blurofinsanity.com/Speeding.html
or try these 71,000 search results from google.
http://www.google.co.uk/search?num=100&hl=en&newwindow=1&q=beating+a+speeding+ti...
I hope I have been of some help and don't hesitate to write to me for more information
Let me know how you get on
Paul.
