Question about Police Lidar Standard Deviations

[Linux23]

I've mentally learned to consider tickets a randomly-applied tax for road usage. Any sane and reasonable driver will still get a speeding ticket occasionally, and the system is set up with this as the intention. So just mentally consider it a lottery tax for driving, say "dang" when your number is up, and pay up.

well that is certainly a unique way to look at this?

 

[zinfamous]

I am concerned that we are going to be Syringered here.

 

[Linux23]

this thread can't be serious. can it?

 

[Paladin3]

OP needs to let us know when the court date is so we can be sure to tune back in to this thread the following day with popcorn ready.

 

[Darwin333]

Thanks. If you have further details please provide it.

I was clocked going 73mph on a 55mph speed limit. I was not looking at the speedometer at the time so I don't know my actual speed. I was following the car ahead of me and cars usually go at the speed limit on this piece of the highway since police are always there!

I try to keep below 65mph all the time for fuel efficiency reasons. In this section of the road I keep AT the speed limit so 55mph. 73 mph is far too high.

My strategy is simple. First I will establish that I am an excellent driver with no previous violations. Next I will establish that I had no inventive or motive to speed, there's actually a disincentive for speeding (gas mileage)!

I will then show evidence that I was averaging far below the speed limit based on the time I left work, average time it takes to go from my chair to my car, and time it takes for my car to leave work and arrive at the spot I was LIDAR'd. I will provide written evidence form my boss on the time I left work since he was there the exact moment I left my chair. I will use google maps to show how I was averaging below the speed limit.

Finally I will bring up the LIDAR confidence interval defense. Because I had no incentive to speed, because I am a safe drive, and because of the possibility of false positives in LIDAR, there is reasonable doubt that I was going above the speed limit.

Man, I was with you on arguing the ticket right up until I read how you intended to argue said ticket. My advice would be to throw away your entire plan of argument and start from scratch but if you do not take my advice please oh please film the court proceedings. Just make it to were your phone camera is sticking out of your shirt pocket, and you do want to wear a nice button up and they usually have a pocket.

 

[Darwin333]

I've heard this in traffic court its irrelevant because the cop could only pull over one.

It's irrelevant all the way around. "Because he/she was breaking the law" is and never will be a valid excuse for breaking the law yourself.

 

[Carson Dyle]

Let's say a police officer measures 100 cars going at exactly the speed limit and the measuring device had a 1% chance of showing a speed 10mph above the speed limit. In this case, the officer will end up ticketing a guy who was actually going AT the speed limit with an inaccurate reading. 100% of the drivers who are ticketed in this case are victims of the reading.

That's some damned twisted logic you got going there.

In any case, do you know what will happen? 100% of those drivers will be found guilty of speeding, unless they can prove the device was in error in their particular instance.

 

[Eli]

It's irrelevant all the way around. "Because he/she was breaking the law" is and never will be a valid excuse for breaking the law yourself.

I didn't really mean it in that regard, I meant that it's generally hard to go too much faster than the car in front of you for very long.. depending on the circumstances, thinking of in traffic here.

I was imaging someone right in front of him, I guess.

 

[Fanatical Meat]

I didn't really mean it in that regard, I meant that it's generally hard to go too much faster than the car in front of you for very long.. depending on the circumstances, thinking of in traffic here.

I was imaging someone right in front of him, I guess.

I get what you're saying but from my experience they'll shut that argument down fast by saying this was your metered/observed speed the car in front is not relevant/nobody knows the speed of the car in front of you
Some people would try stuff like that and the Judge would beat them up a bit but ultimately let them off. From my 3 experiences with traffic court assuming you've had no other issues and were not doing something absurd like 50 mph over the speed limit or in a school zone or driving with suspended license/uninsured you either got off or a greatly reduced fine with a warning like if I see you again I'll double the fine or something similar.

 

[jlee]

and i'd look at him, smile, and jam the throttle to the floor and see who he prefers to pull over. me or that other driver.

Not sure if srs, but I would definitely go for you - in NH, that's a Class A Misdemeanor (up to a year of jail time). I imagine other states are similar.

 

[Darwin333]

As I said, it is not my intent to prove the device is defective or that the operator (cop) didn't use it properly. It is my intention to show that even with everything working properly, it is likely that if an officer runs 40 readings a day he will catch 5 people in a month going 15 mph or whatever number faster than they were actually going. Numbers can change given actual data!

As has already been stated the burden of proof is quite different from an actual criminal case.

Answer this question, which has the greatest statistical probablity:

A. The LIDAR worked properly and accurately recorded your speed within whatever small margin of error it has (probably +/- 1mph)
B. You happened to be the 2% or whatever of the incorrect readings.


If you walk into traffic court and say that there is a 5% chance that the LIDAR was wrong you are in the very same statement saying that there was a 95% chance that it was right. You just proved the governments case against you.

Now if they have to be calibrated like old RADAR units and it wasn't calibrated in whatever time frame they are supposed (ie. supposed to be calibrated every 6 months but hasn't in over a year) to be you might have a case but I don't think LIDAR has to be calibrated. I could be wrong about that but you would have probably found that sort of info by now if I was.

 

[Darwin333]

I didn't really mean it in that regard, I meant that it's generally hard to go too much faster than the car in front of you for very long.. depending on the circumstances, thinking of in traffic here.

I was imaging someone right in front of him, I guess.

Sometimes cops just get the easiest one, sometimes they are able to pull over both at the same time, I dunno they might be ford people so they decide to pull the Chevy over or some dumb crap like that. I was pulled over once and some guy had just flew past me and I was thinking the same thing, who knows why they decide to pull who over.

I thought you were making it out to be an argument in the court.

 

[Darwin333]

That's some damned twisted logic you got going there.

In any case, do you know what will happen? 100% of those drivers will be found guilty of speeding, unless they can prove the device was in error in their particular instance.

I think you need to reread his post again. 99 drivers would not be pulled over and 1, assuming the cop couldn't visually tell a 12mph difference, would get a ticket.

 

[Eli]

Sometimes cops just get the easiest one, sometimes they are able to pull over both at the same time, I dunno they might be ford people so they decide to pull the Chevy over or some dumb crap like that. I was pulled over once and some guy had just flew past me and I was thinking the same thing, who knows why they decide to pull who over.

I thought you were making it out to be an argument in the court.

I was just trying to understand the circumstances. But yeah. I like the lottery analogy, that's a pretty good way to look at it.

 

[Carson Dyle]

I think you need to reread his post again. 99 drivers would not be pulled over and 1, assuming the cop couldn't visually tell a 12mph difference, would get a ticket.

Ah, you're right. But the logic is no less flawed.

Let's say a police officer measures 100 cars going at exactly the speed limit and the measuring device had a 1% chance of showing a speed 10mph above the speed limit. In this case, the officer will end up ticketing a guy who was actually going AT the speed limit with an inaccurate reading. 100% of the drivers who are ticketed in this case are victims of the reading.

100% of those ticketed who just happened to be at or near the speed limit when the device gave an incorrect reading. That's still going to be 1% or less of those ticketed due to a misreading.

 

[Hacp]

Another piece of evidence to add to my list. Law enforcement regularly overstates the certainty in forensics/measurements. The trust me argument won't work anymore.

http://www.nytimes.com/2016/06/04/u...t&contentPlacement=8&pgtype=sectionfront&_r=0

 

[Carson Dyle]

You seriously have it in your little mind that something like that constitutes "evidence" that you can use in a court of law?

 

[Hacp]

100% of those ticketed who just happened to be at or near the speed limit when the device gave an incorrect reading. That's still going to be 1% or less of those ticketed due to a misreading.

Using my example, it will still be 100% ticketed. Lets put it in simpler terms.

Let's say OTC pregnancy tests have a 5% chance to give a false positive. If 100 infertile women took the test, on average, five would show a false positive. In this case, 100% of those who had a positive result aren't really pregnant.

 

[jlee]

Using my example, it will still be 100% ticketed. Lets put it in simpler terms.

Let's say OTC pregnancy tests have a 5% chance to give a false positive. If 100 infertile women took the test, on average, five would show a false positive. In this case, 100% of those who had a positive result aren't really pregnant.

Straw man.

How frequently do processors make faulty calculations and how frequently does the speed of light change in the atmosphere you live in?

 

[Carson Dyle]

Using my example, it will still be 100% ticketed. Lets put it in simpler terms.

Let's say OTC pregnancy tests have a 5% chance to give a false positive. If 100 infertile women took the test, on average, five would show a false positive. In this case, 100% of those who had a positive result aren't really pregnant.

That's not simpler, it's exactly the same fractured logic. If EVERYBODY drove at the speed limit, then everyone ticketed is being ticketed falsely. But they don't. The vast majority are fairly ticketed because the likelihood that the device is wrong is very small _AND_ they're guilty of speeding.

Man, you just aren't playing with a full deck, are you?

 

[JEDIYoda]

Hacp has no clue what this thread is about....nor does he know what he is talking about..........

 

[Hacp]

If EVERYBODY drove at the speed limit, then everyone ticketed is being ticketed falsely.

Glad you realized this. Now let's move one step further, slowly so you can understand. A cop LIDAR's 100 people. 5 were going above the speed limit. 95 were going at the speed limit. There is a 1% chance the device records someone going 10 mph faster than they actually were going. On average, what % of the ticketed drivers were going at the speed limit?

 

[lupi]

That's not the way all things are calibrated.

 

[DaTT]

When is your day in court, and where are you? I'd like to be in the courtroom during your testimony.

 

[DrPizza]

Another piece of evidence to add to my list. Law enforcement regularly overstates the certainty in forensics/measurements. The trust me argument won't work anymore.

http://www.nytimes.com/2016/06/04/us/justice-dept-fbi-scientist-forensic-test.html?rref=collection%2Fsectioncollection%2Fus&action=click&contentCollection=us&region=stream&module=stream_unit&version=latest&contentPlacement=8&pgtype=sectionfront&_r=0

And you are GREATLY overstating the inaccuracy of LIDAR's measurements.

You said you were behind another vehicle, and that vehicle wasn't pulled over. Here's a defense that is 1000 times more plausible: just a wild assumption, but because you took a known avatar and made the skin darker, I'm going to guess that you're darker skinned - black? Middle-Eastern? Indian? Native American? It doesn't matter to me. But, perhaps of the two speeding cars, you were pulled over because you were profiled.