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Chicago Court Throwing Out LIDAR Speeding Tickets
bridgeco writes "Chicago Traffic Court Judges have been throwing out speeding cases in which the driver's speed was measured with a LIDAR. Judges are asking for a special 'Frye Hearing' to determine the accuracy of these devices. Many motorists nabbed for speeding by a laser gun, instead of radar, are seeing their tickets thrown out at Chicago's traffic court because of a legal issue that the city's law department has been unable to overcome. Within the past year judges in Cook County Traffic Court in Chicago determined that speeds captured by lidar were not admissible because the devices had not been proven scientifically reliable in an Illinois court, said Jennifer Hoyle, spokeswoman for the law department, which prosecutes most speeding tickets in the city." (Here's some background on LIDAR from Wikipedia.)
Another problem with using frickin' lasers is that you have to trust the sharks to use them correctly.
With a name like LIDAR, who would doubt the radar's claimed speed?
http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=2009910220360
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I'm sorry we had to meet under these circumstances, but allow me to introduce myself. I'm Colonel Tribune, the Web ambassador for chicagotribune.com.
Looks like the Tribune Co. is really embracing the interweb...
Meantime, I hope I run into you surfing the Web. You can find me on Twitter and Facebook.
...I wonder if Colonel Tribune prefers Farmville or Mafia Wars?
0 = 1 + e^(Alt something)
The link doesn't work. On the other hand, there's a very nice 404 page. It's funny, friendly, and attempts to be informative.
Good error handling is something many of us don't always do well.
Never attribute to malice that which can be explained by mere idiocy.
[$group] failed to go through [$procedure] to have [$new_technology] legally recognized by [$other_group]. As a result all results recorded by [$group] using [$new_technology] are considered legally suspect by [$other_group].
I am Slashdot. Are you Slashdot as well?
The point is, LIDAR is reliable, at least as much as RADAR is. This is just a legal snafu, they will throw out enough that there will be incredible pressure to figure out the legal problems, they will figure them out, and then LIDAR tickets will be enforced again. Never underestimate the power of a determined vendor that has been harmed or the importance of sunk costs in equipment for an agency with very limited funding. Nothing to see here, folks. Move along, please.
Just because I can hook a shark from a boat, I do no offer to wrestle it in the water.
Florida is one of 50 states yet hands out 15% of all traffic tickets.
The residents of Wyoming are going to be pissed if, according to your math, they're going to have to give a dozen speeding tickets to each citizen to bring them up to 2%. Kind of unfair, given they only have 0.17% of the US population.
What is the benefit of LIDAR? Is it more accurate, or just easier to 'aim'?
Both actually. RADAR emits a conical wave of energy that literally splatters multiple lanes. The return signal processor can get Doppler signal back from many vehicles, and reports the strongest signal (or fastest in models that support it). It is then up to the officer to visually determine which vehicle is speeding. It's not infallible, and subject to an officer's decision.
LIDAR on the other hand shoots out a very narrow pulsed beam that targets one specific vehicle at a time. Officer's are usually trained to target reflective parts of a vehicle (like headlights, taillights, license plates, etc.)
There is no trying to figure out which vehicle your measuring, you target, pull the trigger and bam, instant accurate speed.. usually within under 1 second so even though your detector has gone off, it's just telling you you're speed as been taken. Reaction time is NIL.
...in that because its beam is so narrow, that the speed measured is more precisely the speed measured between the target vehicle and the LIDAR gun itself, not necessarily the forward speed of the target vehicle down the road. Since the patrol officer is always sitting off the side of the road, that introduces what's known as the "cosine error" which is actually in the speeder's favor since the LIDAR device will show the officer a slower speed (vehicle's actual forward speed times the cosine of the angle between straight ahead vs a line between the front of the vehicle and where the officer's LIDAR is actually located). Most of the time, the cosine error is negligible, but if the officer is sitting far enough off the side of the actual roadway and the angle is big enough, the cosine error can be several MPH in the speeder's favor.
I have the solution!
It was Colonel Tribune, with the forward-slash, on the URL.
I would be more concerned with the legality of MPH Industries' radar POP mode. In summary, the company is marketing radar guns with a mode that allows officers to obtain speed readings that are at best, inaccurate. Of course, the only place a warning about the inaccuracy of this mode is found, is in the radar's instruction manual. How many police officers do you think read the instruction manuals that accompany their equipment? Reports of people "getting POPped" have shown up in WV, OH, GA, NV, NJ, and NY.
"POP is mode that emits a very brief (67 millisecond) pulse of radar to determine the speed. Its meant to defeat radar detectors. It works because the local oscillator sweep (the "tuner") in most detectors, (especially cheap ones) is too slow to notice this brief pulse. Newer and more expensive detectors have solved this by making a little detour during the sweep to check for POP. It's like flipping through the channels on your TV, but going back to check if your favourite show has started on channel 2 every so often. Except in a radar detector this is happening hundreds of times per second.
POP can be inaccurate because the electronics in the police radar don't have time enough to stabilize. It's like suddenly jumping on your bathroom scale. The pointer with fluctuate violently until it settles down on the the true reading. With POP it can sometimes indicate an inaccurate speed due to this instability. "
grep -iw skynet
Lawmakers and people don't know shit about science and technology. There is no absolute speed or stationary point.
But there are relative speeds, which is why your vehicle's speed is always considered to be relative to the surface of the earth.
Lawmakers may not know shit, but you know just enough to fail to notice the blindingly obvious.
The enemies of Democracy are