How does police radar work?

Dan40 · #1 (**permalink**) 09-29-2009, 08:59 AM

Think about this:

http://www.amazon.com/Ticket-Book-Ro...owViewpoints=1

Wayne Maybury · #2 (**permalink**) 09-29-2009, 02:26 PM

Bill, that is exactly how I plan on doing it. I am going to present the facts as I see them and state that I believe that the office made an error based on the fact that he probably did not see the pickup from his position (his car was well hidden so all he could do was to look at the small side mirror to see what was happening behind him). I will be polite and factual.

Bobcat, I have all 15 points and this could cost me 3 points so I would be left with 12 points. The fine is $249. Neither will break me but what really bothers me is that the officer stopped the wrong guy. The driver of the pickup knew that he had been caught and he must still be laughing about the officer stopping me instead of him.

I spoke to a friend earlier today and he told me that I will probably not get a court date for at least 4 or 5 months. I am going to write down the facts as I understand them so that I do not get confused between now and the time I get to court.

Wayne

bomelia · #3 (**permalink**) 09-29-2009, 10:29 PM

Wayne, thats the problem. The officer did not make an error. You admitted you were over the limit. That has psychological implications for you. The fact that the officer did not catch the one going the MOST over the limit is irrelevant. I have played this one out in my own mind many times. Chances are very good you will never know how many other folks (if any) got a ticket in the exact same situation when you were the worst violator. If you know for a fact that you were not speeding, then hell yeah, I would go to court and raise a holy stink on principle alone. It might not do me any good and it might cost me more, but knowing I am right will possibly shine through and earn me a victory. However, you are putting yourself into a situation where you may very well have to cast your principles aside in order to prove your point, and that will shine through as well.

Better to ask mercy from the court and permission to take a "safe driving" course (to get out of the points) then to argue that someone was breaking the law more than you were. It is after all, about the points, right? You could say "yes sir, I was in a moving parking lot that on average was above the limit. I was going with the flow. I think what most likely triggered the radar was a this big duelie passing me at the same exact moment. Unfortunatley for me, I got caught, and fortunately for him, he did not. All I am doing here today is asking for mercy and access to a safe driving course at my expenese to mitigate points on my record... I will gladly pay any assessed fees as I was no more better than the duelie going by me at 114Km/hr"

I think you will find that in another form in "How to win friends and influence others"

Mike

trularin · #4 (**permalink**) 09-30-2009, 05:27 AM

Radar is a targeted wave at a designated frequency. The designer knows how long each wave is and based on emission and reflection times, the speed can be determined.

Here is the problem: it is a line of sight device. Any object that reflects the wave has to be in the line of sight and there actually is no way to tell what object is providing the reflection unless you have a differential imaging system.

Hope this helps.

RET_COP · #5 (**permalink**) 12-06-2010, 04:54 PM

Ran radar for 25 years, big, small, side mounted, dash mounted, laser, you name it. Bobcat hit it on the head, The radar pickes up the strongest signal which most of the time is the largest surface area. And in close dense traffic this can be problematic for us to figure out what vehicle it is reading. A seasoned cop can cut through the obvious and make a statistically correct decision. A seasoned cop will HOPEFULLY let a possible error go, as there is always another big fish to catch. I did not get hung up on the average "over the speed limit cars". I had a job to do... but there was always a really crazy driver on the road, and that was the one that flew by you when you were giving a ticket out to a mild speeder. Now that pissed me off. I hold the record for recording the fastest speed OVER the posted limit. 108 MPH . I never caught that motorcycle.

Lou

Wayne Maybury · #6 (**permalink**) 12-07-2010, 07:36 AM

Lou

When I was much younger, I got more than my share of speeding tickets.

Of course I tried to talk my way out of them or politely asked the officer if he could give me a break, etc. I never said that I wasn't guilty, if I was guilty as I figured that would just piss off the officer.

In this case, I know that the pickup was going faster than me as he passed me and then applied the brakes as he changed lanes and cut in front of me. I am relatively sure that the officer's view was limited so he probably did not see the pickup therefore he assumed that I was the one speeding. I feel that I had no choice but to plead not guilty. The judge may, or may not agree with me but at least I will have my chance in court.

What really got me was the officer saying to me that the radar told him that I was the one speeding. My impression was (and you have confirmed this) that the radar will pick up the fastest moving vehicle or possibly the speed of the biggest vehicle. In this case, both were the dual-wheel pickup.

Wayne

RET_COP · #7 (**permalink**) 12-07-2010, 02:57 PM

Wayne, Good Luck in traffic court. You could plead good drivers record and in several states this ticket can and will be filed. It usually is a first ticket kind of situation.
The radar cannot tell the police officer anything, it merely recorded the speed of a vehicle in the cone of the radar, which is rather large and CANNOT pinpoint an individual vehicle with any certainty like a laser can. Its up to him to decipher the situation which you can bring up some doubt. The rear view mirror vision is a good point. Unless the officer has a bad track record with the judge, he will usually trump the rebuttal from the accused without a lawyer.
With a real charming and sound argument, and an officer with some doubt about what he determined ( and smile and say hi to him if you see him in court)

, may agree with you.
Lou

Wayne Maybury · #8 (**permalink**) 12-10-2010, 09:15 AM

Thanks for the encouragement Lou.

I had my share of tickets many years ago but I have only had one speeding ticket in the past 10 years. About 9 or 10 years ago I was rushing to catch a flight and I had no idea that a radar trap was set up on the entrance to that airport. Since then the only thing I have had was one parking ticket until now. I drive a lot so I have been lucky not to have had more tickets but I do have a very good record.

I honestly think that the officer did not have a good view of the situation. He had to pick somone and in my opinion, he got the wrong guy. I hope the judge sees it my way. My wife was with me so it will be 2 against 1, for whatever that's worth.

Wayne