• FreeAdvice has a new Terms of Service and Privacy Policy, effective May 25, 2018.
    By continuing to use this site, you are consenting to our Terms of Service and use of cookies.

LIDAR calibration question

Accident - Bankruptcy - Criminal Law / DUI - Business - Consumer - Employment - Family - Immigration - Real Estate - Tax - Traffic - Wills   Please click a topic or scroll down for more.

mcshiny

Member
What is the name of your state (only U.S. law)? CA

I was cited with a VC22350 (Basic Speed Law) violation and I requested discovery for my case, which involved the calibration records for the LIDAR gun. In the records I received, it says the last time they calibrated the gun was in June 2008. Does anyone know if have a good defense in saying that the calibration is over a year and a half old and that the accuracy of the gun may be questionable? I'm not sure how often a LIDAR gun needs to be calibrated, but I thought that doing an annual calibration was recommended. Any help out be appreciated!
 


JIMinCA

Member
I'm not sure of any law that states any requirement for calibration of the lidar except in 40802 when the survey is more than 5 years old. So, do you have a copy of the survey? Does it justify the limit? How old is the survey?
 

mcshiny

Member
There was no survey included in the discovery unfortunately. Very basic stuff they gave me. Copy of the ticket, the cop's certification to use LIDAR, and the LIDAR calibration.
 

Maestro64

Member
It is manufacture specific unless a state has a more specific law which I believe CA does not have calibrate requirements. So you would have to find out what the manufacturer specifies in their manual on the required calibration. Some require yearly other say as much as 3 yrs.

The officer is not require to produce the engineering survey, you have to contact Caltrans or the local town to get a official copy.
 

mcshiny

Member
I'm not familiar with asking for surveys from CalTrans. Can someone point me in the right direction to request it?

And my trial by written declaration (TBWD) is due in 3 weeks, so in case I don't get the survey back in time, isn't it the burden of the prosecution (in this case, the cop) to show that the survey is less than 5 years old? Innocent until proven guilty, but I'm not sure if I make a statement in my TBWD that proof needs to be shown of the engineering survey, and the cop doesn't provide it, if I would be found in favor.

Also, I was cited on a Highway. Not sure if that makes a difference as to whether a survey exists for it.
 
Last edited:

racer72

Senior Member
And my trial by written declaration (TBWD) is due in 3 weeks, so in case I don't get the survey back in time, isn't it the burden of the prosecution (in this case, the cop) to show that the survey is less than 5 years old?
The DA will be prosecuting you, the officer will be his/her witness against you. They both only have to provide evidence to be used against you, they do not have to provide evidence to the court that would be to your benefit, that is your job.

Innocent until proven guilty, but I'm not sure if I make a statement in my TBWD that proof needs to be shown of the engineering survey, and the cop doesn't provide it, if I would be found in favor.
Read my last sentence above.

Also, I was cited on a Highway. Not sure if that makes a difference as to whether a survey exists for it.
Again, that is your job to find out who owns the highway.
 

I_Got_Banned

Senior Member
I was cited with a VC22350 (Basic Speed Law) violation and I requested discovery for my case, which involved the calibration records for the LIDAR gun. In the records I received, it says the last time they calibrated the gun was in June 2008. Does anyone know if have a good defense in saying that the calibration is over a year and a half old and that the accuracy of the gun may be questionable? I'm not sure how often a LIDAR gun needs to be calibrated, but I thought that doing an annual calibration was recommended. Any help out be appreciated!
Its every three years irrespective of how old the survey is... See section 40802(c)(1)(D) which states:

(D) The radar, laser, or other electronic device used to measure the speed of the accused meets or exceeds the minimal operational standards of the National Traffic Highway Safety Administration, and has been calibrated within the three years prior to the date of the alleged violation by an independent certified laser or radar repair and testing or calibration facility.​
 

I_Got_Banned

Senior Member
I'm not familiar with asking for surveys from CalTrans. Can someone point me in the right direction to request it?
You call the Caltrans district office for the area where you were cited and you ask them for a copy of the Engineering and Traffic Survey for the road segment where you were cited (the location of the violation from your citation). If the are responsible for maintaining that road/highway, they will have it... If not, they should be able to direct you to the entity who can provide you with a copy.

By the way, what happened to your other 22349(a) and 22348(b)???

https://forum.freeadvice.com/speeding-other-moving-violations-13/help-vc22349-ticket-involving-lidar-505269.html
https://forum.freeadvice.com/speeding-other-moving-violations-13/vc-22348-b-can-you-do-trial-written-declaration-charge-481169.html

By my count, and assuming you lost those other two (1 violation point for the 22349(a) & 2 violation points for the 22348(b)), and this would make for your 4th violation point within a 12 month period which can and probably will result in an administrative 6 month suspension by the DMV + a 1 year probationary period (during which you are not allowed any additional points otherwise your suspension will be for a full year).
 
Last edited:

JIMinCA

Member
mcshiny,

You are getting a lot of bad information here:

1. If you requested the survey in your discovery request, it IS the prosecution's responsibility to provide that to you. You can get a copy for yourself from CALTRANS (and you should), but you can argue in court that a survey should not be introduced as evidence since you asked for it in discovery and it was not provided.

2. There will be no prosecutor. In CA prosecutors are not required to attend infraction trials. They interpret that to mean (incorrectly, I might add) that they have no responsibilities at all. The cop will be the only one dealing with your case.

3. lidar calibrations are NOT required every three years all the time. That requirement is only used for the purpose of extending the speed survey from 5 to 7 years. Read VC40802(c)(1) very carefully.
 

mcshiny

Member
You call the Caltrans district office for the area where you were cited and you ask them for a copy of the Engineering and Traffic Survey for the road segment where you were cited (the location of the violation from your citation). If the are responsible for maintaining that road/highway, they will have it... If not, they should be able to direct you to the entity who can provide you with a copy.

By the way, what happened to your other 22349(a) and 22348(b)???

https://forum.freeadvice.com/speeding-other-moving-violations-13/help-vc22349-ticket-involving-lidar-505269.html
https://forum.freeadvice.com/speeding-other-moving-violations-13/vc-22348-b-can-you-do-trial-written-declaration-charge-481169.html

By my count, and assuming you lost those other two (1 violation point for the 22349(a) & 2 violation points for the 22348(b)), and this would make for your 4th violation point within a 12 month period which can and probably will result in an administrative 6 month suspension by the DMV + a 1 year probationary period (during which you are not allowed any additional points otherwise your suspension will be for a full year).
I actually made a mistake, this violation I am currently dealing with now is the same VC22349(A) I mentioned before. And for the VC22348B, I got lucky and had it dismissed. So, no points yet accrued thankfully. I am going to try to at least get traffic school at the very least on this charge. I owe this message board a ton of thanks for all the help I got on the VC22348(B). And thanks for the into on CalTrans as well.
 

mcshiny

Member
Well, then you're SOL on the survey as one is NOT required to justify a 65mph speed limit.
I kind of had a feeling about that. It was the reason why I wondered if there would be a survey for a highway since I didn't think a survey would actually pertain to me in this situation. Just got my information mixed up. I'm actually kind of relieved in a way the survey doesn't apply to me because now I don't have to go jumping through hoops to get it. Stupid, I know, it's something that could have possibly helped me but I kind of just want this to be over with. Thanks again for the help.
 

Maestro64

Member
If you were LIDAR on a highway you need to go another path on your defense.

LIDAR has some fundamental issues which allows for it to measure speeds which are not accurate and it is subject to error. Research Slip or Panning errors as it relates to LIDAR. There are misconceptions that LIDAR is precises since it is a Laser. It is not the laser as seen in laser pointers, which has a very thin beam of light it actually it is an invisible infrared beam that will spread over distance and the officer has no way of knowing whether the beam is actually hitting what he is looking at. Also as the distance increases there is a greater chance the returning signal could be from another vehicle. To reduce this chance of happening the officer is required as defined in the user manual to do a check each day to verify the sight on the LIDAR and beams are aligned properly. Many time this is not done.

Anyway if you research LIDAR defenses and operation you will learn what you need. Since it obvious the documentation defense method may not work in your case.
 

I_Got_Banned

Senior Member
LIDAR has some fundamental issues which allows for it to measure speeds which are not accurate and it is subject to error. Research Slip or Panning errors as it relates to LIDAR. There are misconceptions that LIDAR is precises since it is a Laser. It is not the laser as seen in laser pointers, which has a very thin beam of light it actually it is an invisible infrared beam that will spread over distance and the officer has no way of knowing whether the beam is actually hitting what he is looking at. Also as the distance increases there is a greater chance the returning signal could be from another vehicle. To reduce this chance of happening the officer is required as defined in the user manual to do a check each day to verify the sight on the LIDAR and beams are aligned properly. Many time this is not done.
That's not going to work especially when officers, and in their often scripted testimony, will say something to the effect of "I observed a vehicle traveling at a high rate of speed, visually estimated its speed at X mph and confirmed that estimate with a Lidar reading of 'X + or - 2' mph... gave chase, ... etc..."
 

mcshiny

Member
If you were LIDAR on a highway you need to go another path on your defense.

LIDAR has some fundamental issues which allows for it to measure speeds which are not accurate and it is subject to error. Research Slip or Panning errors as it relates to LIDAR. There are misconceptions that LIDAR is precises since it is a Laser. It is not the laser as seen in laser pointers, which has a very thin beam of light it actually it is an invisible infrared beam that will spread over distance and the officer has no way of knowing whether the beam is actually hitting what he is looking at. Also as the distance increases there is a greater chance the returning signal could be from another vehicle. To reduce this chance of happening the officer is required as defined in the user manual to do a check each day to verify the sight on the LIDAR and beams are aligned properly. Many time this is not done.

Anyway if you research LIDAR defenses and operation you will learn what you need. Since it obvious the documentation defense method may not work in your case.
Thanks for the info, Maestro! Good stuff. I had heard that LIDAR has some issues with accuracy and that some states have not taken judicial notice because of it. Thanks for educating me on the beam of the laser. I've tried to google some information on specific LIDAR defenses but I haven't really found any real good defenses for it. Seems like not as many people have tried to fight LIDAR case as opposed to RADAR.
 

Find the Right Lawyer for Your Legal Issue!

Fast, Free, and Confidential
data-ad-format="auto">
Top