Radar taken from an opposing officer??

[JP232]

Does anyone have any information on how radar taken from an officer driving the OPPOSITE direction works? I've never even heard of such a thing.

I was just cited the other day using this, and his estimation of my speed was higher than it should have been. Wouldn't this fall under most speed trap laws since it would require a combination of his speed (unknown) versus mine? How does this even work?

Thanks.

[Your Mentor]

Radar works in any direction. It always has. In fact, it works best when the target vehicle is coming in the opposite direction. Radar is only a speed trap if it's deployed on a non-surveyed, prima facia street. As for his radar's speed being higher, that's usually because the violator stabs the brakes as soon as they see the officer and THEN looks at their speedometer. We use digital radars now which are are extremely accurate. Also, current traffic radar is target specific based on the direction. In other words, the officer sets the radar to opposite-approaching in your case. The radar disregards vehicles ahead moving in the same direction. Say you're closing on a black and white at a high rate of speed. The officer can select same-approaching and get your speed before you realize you're approaching a cop. Also, the radar signal is a microwave signal with a range of well over a mile on flat stretches of road. So many times an officer has had you one radar long before you ever notice him or her. We tend to look far ahead of the traffic immediately in front of us (known as a high visual horizon). Most civilians don't notice traffic beyond their immediate traffic space, usually about five car lengths. So we always tend to surprise people when we stop them but understand that we will likely see you long before you see us.

[Flying Pig]

BAAAAM....next question

[JP232]

Thanks for the response, that helps.

I hear a lot about radar needing a current engineering survey. If I plan to contest it in court, which I know isn't adviseable, do I need to request the survey in advance, or is that something officers must have with them?

[dig]

Thanks for the response, that helps.

I hear a lot about radar needing a current engineering survey. If I plan to contest it in court, which I know isn't adviseable, do I need to request the survey in advance, or is that something officers must have with them?
Sounds like a guaranteed way to get a ticket for ANYTHING they can find...lol.

[Mac]

Thanks for the response, that helps.

I hear a lot about radar needing a current engineering survey. If I plan to contest it in court, which I know isn't adviseable, do I need to request the survey in advance, or is that something officers must have with them?
Not required to be in their possession. In a related vein, I read in some attorney's driver that if you're cited for radar you should ask for the officer's current radar certification.....that's not in their possession either, and they aren't required to show it to you.

As to the original question - radar works while stationary or moving, going in the same or opposite directions, from the front or rear. All the stories that attorneys like to tell about trees being clocked at 300 mph and so forth are artifacts and half-truths. A trained operator can easily sort spurious readings out from the "real deal".

[Tom]

I think its funny to listen to people talk about radar...likes its "new" technology. Folks....radar was used successfully during and sometime before World War II. (Not for freeway speed but several much more critical operations.........ie. submarine range finding) It is a proven device and method and is incredibly accurate in the hands of a trained operator.

Tom

[Your Mentor]

I'm with you Tom. I'm always shocked when people pose the 'opposite direction' question during traffic stops. Sure, traffic radar only operated in stationary mode when it was first deployed. It's been used in moving mode since 1971. The advent of digital units in the early 90's opened up the technology even further. I have yet to testify regarding our current model's ability to track two targets simultaniously. As for all of the documents, I have gotten into the habit of providing them, along with a diagram, to the judge and defendant before I testify. In several cases it's caused the defendant or attorney to enter a guilty plea immediately. I got in the habit when I had to act as the statewide Radar Training Coordinator for about six months in 2003. I've experience one hired gun who subpoened all of the documents weeks before a trial. Didn't do anything to help his client's case. And one thing our officers are generally not aware of is that the CHP basic operator's course is 54 hours, not the legally mandated 24 hours. That's because the 30 hours of field training is considered part of the cirruculum. Remember this next time you testify. Also, make use of any radar instructors in your area, if you have them, as experts in court. It's perfectly acceptable and good for the instructor. It also takes a lot of pressure off the officer if you're dealing with a nit-picking attorney. Something to keep in mind.

[Erin]

I heard you can beat radar by driving with a penny in your mouth :lol:

[makakona]

so, am i understanding this correctly... a radar in a travelling vehicle can accurately catch the speed of another vehicle travelling towards it?

[aviator]

so, am i understanding this correctly... a radar in a travelling vehicle can accurately catch the speed of another vehicle travelling towards it?

As long as the radar device knows the speed of the police vehicle, that speed can be subtracted from the closing speed, thus revealing the speed of the vehicle in violation.

[23109]

so, am i understanding this correctly... a radar in a travelling vehicle can accurately catch the speed of another vehicle travelling towards it?

Yes, very accurately. Having been radar certified recently, it's a most excellent tool to have if you're not working on a freeway.

[Your Mentor]

Hey Makakona,
Haven't heard from you in a while. In answer to your question, YES. The logic unit in a radar actually has a very simply job to perform. That job is easier than basic math on a handheld calculator. The logic unit is the brains of the radar. The antenna sends out a specific microwave transmission which is bounced off the pavement and calculates the patrol car's speed. It sends out a separate signal, simultaniously, which bounces off the target vehicle. The speed it 'senses' on the target vehicle is it's closing speed. The unit simply subtracts the patrol car speed from the closing speed to end up with the target's actual speed. That's why one important part of the tracking history is to confirm that the patrol car's speedometer matches the patrol speed reading on the display unit. If they don't match, the unit is experiencing one of several known 'effects' and so the target speed is to be disregarded.
YM

[makakona]

ym, what with all the laundry washing, diaper changing, house cleaning, and meal preparing, it's a wonder i find time to sleep some days, ha.

interesting! we were stopped in wyoming once, while driving from virginia to california. it was late at night, in the winter, and we were on a somewhat winding road in the mountains. a sheriff coming the opposite direction blew past us, turning on his lights just as he passed our truck. we kept driving, wondering if the lights were for us or...? we decided to play it safe and pull over. the guy was a royal jerk and said he got us on radar doing some ridiculous speed 30 over. he was totally full of it because i had been riding my husband about his speed because there were deer everywhere and i'm a paranoid chick, haha. i was being a naggy wife, checking the speedometer every few minutes and harping on him. we knew we had absolutely not been going that fast and argued and the guy eventually dropped it and let us go. i always assumed it was because he couldn't have gotten us on radar approaching like that, but i guess it was something else... thinking back to the road conditions, i wonder if he even had it on.

when we stopped for gas a bit later, the cashier was chatty and we talked about the stop. she asked if it was "the big guy or the little guy." we confirmed it was "the big guy" and she said, "oh, that's jason, he hates everyone and everyone hates him." ha! she surmised he thought we'd be an easy cite because we had out of state plates (virginia) and would just send the cash in.

[dw]

I have yet to testify regarding our current model's ability to track two targets simultaniously.

I can say I have and it went well... Being a Physics geek, I look forward to the opportunity to testify on RADAR cites -- I geek-out and enjoy explaining the concepts.

[David]

I heard you can beat radar by driving with a penny in your mouth :lol: No, no no. :rolleyes:

Having a penny in your mouth keeps you from getting busted for DUI, not speeding. :biggrin: ;)