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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.
http://www.chicagotribune.com/news/chi-speeding-tickets-09-nov09,0,7869040.story
With a name like LIDAR, who would doubt the radar's claimed speed?
http://www.honoluluadvertiser.com/apps/pbcs.dll/article?AID=2009910220360
mu
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?
http://www.chicagotribune.com/news/chi-speeding-tickets-09-nov09,0,7869040.story
I find being offended by me offensive.
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.
Here's a working link to the article: http://www.chicagotribune.com/news/chi-speeding-tickets-09-nov09,0,7869040.story Note: The forward slash at the end of the link in the summary is what is throwing off chicagotribune.com
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.
They obviously hired mutated sea bass here.
KICK HIS ASS, SEABASS!!!!
Imagination drew in bold strokes, instantly serving hopes and fears, while knowledge advanced by slow increments...
...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
That happened to me once in Mobile, Alabama. I pulled into the far left lane on I-10 to pass a car in the next-to-left lane. I got about halfway done passing them when a cop whizzed up behind me. Not wanting to get a speeding ticket, I slowed down to 55 MPH. Of course, the car to my right did the same thing, and we ended up side-by-side.
Not really wanting to be stuck in the left lane, and not wanting to get a ticket, and since the guy next to me wasn't slowing down, I slowed down to drop in behind him and let the cop past. When I did, he turned on his lights and pulled me over. He proceeded to lecture me about how the far left lane was a passing lane, that when a car comes up behind me like he did, I needed to speed up and get out of the way, blah, blah, blah.
Of course, I totally agree with him. That's precisely what I do under normal circumstances--avoid cruising in the left lane. People who do that drive me nuts. Of course, I guess the significance of the fact that he was a cop was completely lost on him, that the reason why I was engaging in this behavior was because I was afraid that he'd give me a speeding ticket.
Truth is, I have very little respect for traffic cops for that kind of crap. Just last night, I was in gridlock at an interstate entrance in Atlanta, Georgia. No one could move anywhere because of how stupidly they have the entrance ramps and the lanes configured on the interstate. At the particular entrance ramp I was trying to get onto, people habitually engage in extremely frustrating and dangerous behavior, such as blocking intersections, pulling left into an intersection from the right lane to get around someone waiting for a light, etc.
Meanwhile, there's an HOV entrance that dumps you right in the right place if you're trying to get on I-85 that is virtually unused. As a result, people trying to get on either of the two main arteries out of town, I-75 and I-85, have to cram onto a one-lane entrance ramp that is completely blocked because just after getting on, people are having to muscle their way to get in the right place since the interstates split about a mile after the ramp.
So after sitting there for around 15 minutes and not moving, I took the HOV entrance ramp. There were two cops at the bottom giving people tickets. Fortunately, they either didn't see that I was alone, or they were busy with the people they were ticketing, because I got away with it. And you know what? In the same situation, I'd pick safety over the law any day. The fact is that in my opinion, those police officers should have been at the top of the entrance ramp directing traffic, not at the bottom creating more problems.
Of course, directing traffic at the top of the entrance ramp would have only resulted in more safety, not the revenue generation of $150 HOV violation tickets. So guess which one they decided to do.
The worst was one night when I saw a cop in the right lane watch a guy swerve across three lanes and onto an exit ramp because I guess he just noticed he was supposed to get off. I damn near slammed into him. The cop just kept going like nothing happened. I guess he had met his quota for the day.
Anyway, yeah, to hell with 'em. It's too bad, because I normally have a lot of respect and admiration for people who put their lives on the line for us every day. But these guys are just a bunch of tax collectors with guns.
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
I had a physics teacher in high school who tried to get out of a ticket for running a red light by using a whiteboard and some equations. She recorded the yellow light duration and measured it. She showed that given the weight of her van, or presumably some stopping distance numbers, had she been going the speed limit when the light turned yellow, there was a range of positions she could have been in at that instant for which she'd have had neither the distance necessary to stop nor the time necessary to get through the light. She won.
Just modulate the beam: Turn it off, and back on at a known, sane interval.
When the interval varies (due to doppler shift), measure the difference in frequency.
Done.
No DC-to-daylight processing of gee-whiz THz signals required. The the carrier frequency (the frequency of the laser beam, in this case) is not important for this to work, as long as you can reliably detect its modulation. Many of these parts must already be in use in existing LIDAR systems, so that the machine can discriminate between its own little point of light and all the background noise around it (daylight).
It's all pretty simple, old-hat tech. Plain old regular amplitude modulation, as described above, would be fine, but there's a lot of other methods which might work just as well.
Kid-proof tablet..
...when seconds count, the cops are only minutes away.