Radar ?

[madland]

How accurate is the rear-facing radar in a CHP patrol unit sitting stationary and faced in the direction of travel as the traffic he's trying to monitor? How can he accurately get 2 vehs at the same time? Got pulled over last month on the way out to the desert pulling the trailer. I was maybe going 60mph (yes I realize 55mph is the speed limit while towing). My nephew was driving his Rv/box trailer combo and following us. This was only his second time driving/towing so there was no way we were gonna be pushing the speed limit..the desert is not going anywhere..we get there when we get there. As we passed the patrol unit sitting there..I checked my speed and thought nothing of it since there was plenty of traffic going faster than we were. Then I see him in my mirror with lights on..I was about 1/2-mile from exit and wanted to pull off fwy to avoid being on the shoulder of a busy fwy and thus putting my family in danger. He's driving next to me telling me to pull over..I knod ok..almost to the exit..he pulls in front of my truck/5th wheel and starts break-checking me to get me to stop!!! He should obviously know this thing doesn't stop on a dime!! When he asks why I didn't pull over I explained the above statement..his response.."Oh..". He said he got us on radar doing 73 but put 65 on the ticket. I explained there's no way we were going that fast with my nephew's inexperience. He writes us both tickets. $495..my nephew can always go to traffic school..but I want this tossed so there's no point on my record (Class-A). While I appreciate LEO's doing their job..go after the Chevy Tahoe that passed us with no weight-dist. hitch or sway-bars on his toyhauler who couldn't keep his rig in one lane to save his life..not the guy obeying the law. Thanks in advance for your input and again for the job you do!!

[NytWolf]

While I understand your question, I'm not sure what it has to do with your ticket. CHP have a forward-facing RADAR and a rear-facing RADAR -- and they are separate units. As far as accuracy, they are as accurate as they are individually calibrated.

I'm not sure how you can challenge a ticket though, because I'm sure you are already aware the speed limit for ANY vehicle with a trailer is 55MPH regardless of the posted speed.

And don't tell the LEO how to do their job -- it's up to the LEO to choose who he pulls over.

BTW: I'm not a LEO.

[JS89]

The courts don't care that you have a class A and don't want the point on the record, in fact most judges/commissioners will expect you to be more cognizant of traffic laws. Because I was not there I will go off of your story being 100% factual. You admitted going 60 when you should have been traveling 55. Take responsibility for your actions. BTW you were not the guy that obeying the law, of you were, than you would have been traveling 55.

[BigDogatPlay]

The RADAR will always read the largest target that is closest to the antenna. Unless the two vehicles are side by side and the officer can observe them travelling at the same speed I'd think it not possible to get two vehicles at the same time.

That said, the officer could take leading vehicle from one antenna and then read the trailing vehicle off the other antenna after they passed.

If the equipment is in proper calibration then the only challenge is to the observations and veracity of the operator.

[Steyrlp10]

Do some agencies now employ the use of lasers to determine if a motorist is speeding? Something I heard, but wasn't sure and thought one of you would know, thx.

[BigDogatPlay]

Do some agencies now employ the use of lasers to determine if a motorist is speeding? Something I heard, but wasn't sure and thought one of you would know, thx.

CHP deploys LIDAR units all over the state, and many local agencies are going to them.

[madland]

The courts don't care that you have a class A and don't want the point on the record, in fact most judges/commissioners will expect you to be more cognizant of traffic laws. Because I was not there I will go off of your story being 100% factual. You admitted going 60 when you should have been traveling 55. Take responsibility for your actions. BTW you were not the guy that obeying the law, of you were, than you would have been traveling 55.

Please Yoda, spare me your rhetorical insight, I'm sure you've never driven over the posted speed limit right?! Right... That being said, I take full responsibility for my driving 5+mph over the speed limit. The last time I had a speeding ticket was nearly 20yrs ago as a teenager and my CDL for nearly 14yrs..also a clean record. So I'd go as far to say I'm a pretty good driver and not one to drive too far above and beyond the posted speed limit.

My issue is with how the officer can get me and my nephew on rear-facing radar when he (nephew) is about 60-70yds behind me. Doesn't it scan in a general direction and to get a specific vehicle it would have to be done manually right? Given the distance between us and the fact that other traffic was driving faster than we were is where I find fault with this. While I figure we won't get out of the ticket, at least maybe get a reduced fine. Also, he puts on both tickets we were both doing 65mph in one area, and in another area he puts us doing 73mph on radar?! I don't get it. And not that this will change anything but when the officer got in front of me and forced me to stop on the shoulder by brake-checking me he 1)not only put himself and my family in danger with this unsafe manuever 2)by not allowing me to safely exit the fwy and instead sitting on the shoulder of a busy fwy he put us in danger again. Just my .02 on that. Thanks to those that contributed useful information. And to all the LEO's out there, again my thanks for the job you do!!

[Ron-Solo]

Don't ask the question if you are going to complain about the answer. You admit you were speeding, so take your lumps or take a chance and fight it.

There is no try, only do....

[cowboykenny]

I don't know how it is done but the radea uses a formula to figure the speed from the front to the rear facing radar. An officer from an adjacent city i know uses the front /rear radar and and a lidar . I have yet to see him loose in traffic court he is very well versed in the use of the units as most officers are. It's not like officers just pick up a radar like a new tool and take it out for a test run. First they must attend at minimum a 40 hour POST approved course.

Just my 2 cents

[retired]

How accurate is the rear-facing radar in a CHP patrol unit sitting stationary and faced in the direction of travel as the traffic he's trying to monitor? How can he accurately get 2 vehs at the same time?

This is the only part of your first post that is necessary and appropriate. Per the rules for this specialty forum, you may ask a question of the active leos and retired leos here in a civil manner. You did so, but then decided to include your particular experience, which wasn't necessary to answer the question you posted.

Please do not come into the leo forum and expect an active/retired leo to explain why a leo you had an experience with did what he did. We weren't there and did not observe the incident, nor do we know what the leo was thinking.

Thank you for your cooperation.