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I live in Ireland and recently my wife got a speeding ticket having supposedly been caught by a mobile speed detector van. She was pretty certain that she hadn'

I live in Ireland and recently my wife got a speeding ticket having supposedly been caught by a mobile speed detector van. She was pretty certain that she hadn't been speeding as she knows the particular stretch of road is notorious for hidden speed traps. The court summons photo had the GPS co-ordinates of the vans location embedded in the corner. So I types them in to Google Maps and it supposedly showed that the van was 50 meters away from the road in a farmers field. I tried again with other mapping sources including Ordnance Survey Ireland - all produced the same result. So our case was simple, if the GPS in the van was so inaccurate then that called in to question the accuracy of the rest of the attached equipment - including the speed detection gear. So I built up a portfolio of documents from both government, commercial and academic sources stating that the GPS equipment in the van should have been more accurate - to at least 5m and ideally more than that. I was also able to call upon my experience having worked on various GIS systems and on the development of lone worker emergency beacons in the past. When I spoke for my wife in court the prosecutor asked me if I was was a certified GPS engineer. I said that I didn't believe such a title existed and that I was offering evidence based on my professional experience. But that was enough to sway the judge who said that unless I had someone from "GPS" [sic] with me than my evidence counted for nothing. Fair play to the guy in the article for putting up a fight.

pwg 9y ago
If you have to do this again at any point, you will likely find more success if you attack the accuracy of the speed measuring equipment, and specifically any traceable calibration of that equipment. Calling into question the accuracy of the GPS location fix in the photo did not directly say anything about the speed measuring device. This is because the speed measurement device was very likely not the GPS locator unit that stamped the photo. The speed measuring device was likely an independent radar or laser unit. The prosecution should bring with them proof that the unit had been field tested that day to verify correct functioning andd field accuracy, and as well should bring the calibration evidence showing professional calibration of the speed measurement device. But unless you question the speed measurement device itself, they have no reason to say much about the calibration status of the device. And since most defendants argue simply "I wasn't speeding" the prosecutors sometimes get lazy and leave the calibration documentation behind. If you question the calibration and they don't have the requisite evidence, then you've got something you can use to convince the judge to rule in your favor.
- DoubleGlazing 9y ago
  The prosecuting Garda Sargeant could not provide a calibration certificate for the speed detector, but the judge still didn't care. It was just a production line

pwg 9y ago

If you have to do this again at any point, you will likely find more success if you attack the accuracy of the speed measuring equipment, and specifically any traceable calibration of that equipment. Calling into question the accuracy of the GPS location fix in the photo did not directly say anything about the speed measuring device. This is because the speed measurement device was very likely not the GPS locator unit that stamped the photo. The speed measuring device was likely an independent radar or laser unit. The prosecution should bring with them proof that the unit had been field tested that day to verify correct functioning andd field accuracy, and as well should bring the calibration evidence showing professional calibration of the speed measurement device. But unless you question the speed measurement device itself, they have no reason to say much about the calibration status of the device. And since most defendants argue simply "I wasn't speeding" the prosecutors sometimes get lazy and leave the calibration documentation behind. If you question the calibration and they don't have the requisite evidence, then you've got something you can use to convince the judge to rule in your favor.

DoubleGlazing 9y ago
The prosecuting Garda Sargeant could not provide a calibration certificate for the speed detector, but the judge still didn't care. It was just a production line