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The Lowdown on Lidar

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Re: The Lowdown on Lidar

#101

Post by vaadu »

Karunamon wrote: post #40
meritt wrote: post #14

Earlier quoted context omitted.

Because video cameras are arguably illegal. You can't face your accuser in court, therefore it should be thrown out. Got a speeding ticket from one of these lovely cameras in the state of Iowa, then I was sent a bill from some company in Phoenix with bold threats that if I didn't pay the fine, it'd be submitted to a collection agency and negatively impact my credit score (because otherwise I'd just have not paid it.…

This is a common myth. The camera is not your accuser; the state is, using the camera as evidence of your violation. It would be no different than a security camera catching you breaking into a building. The camera doesn't sue, the owner of the building does.

This is not a myth. The government wants people to think this because they don't want the veracity of the camera being questioned. That would be too fair for a system based on cash-register justice.

Re: The Lowdown on Lidar

#102

Post by ylhert »

gknoy wrote: post #91
ylhert wrote: post #75

LIDAR sucks and there is no judicial notice on it in California. If you ever get a LIDAR ticket, do a trial by written declaration (or TBD). Just state that you dispute the validity and accuracy of the LIDAR reading and they'll usually throw it out. Remember to ask the officer(after he has given you your ticket) what model laser/radar detector he was using, and at what distance he measured you at. Anything over 800/1…

>> Remember to ask the officer(after he has given you your ticket) what model laser/radar detector he was using, and at what distance he measured you at. That's an interesting point. Would that be admissible, though? Wouldn't you saying "He said it was at X feet" would be considered hearsay in court, versus a cop saying "I took a reading at X/2 feet"?

He/she should normally write it on the ticket(pretty sure they have to, it's always been there on tickets I've seen), but if you can get him/her to say it out loud, it's evidence that you can probably use against him/her. Also you should record your interactions with all officers. My final not a lawyer advice on beating speeding tickets: shut your mouth and don't answer the officers questions. If the officer asks how fast you were going, nothing you can say helps you, especially "I don't know". Just do your best to be polite, but firm, and don't give him anything more than a nice attitude

Re: The Lowdown on Lidar

#103

Post by Alupis »

diminoten wrote: post #94
kudu wrote: post #83

Why do HN mods keep changing the title from meaningful ones, which make the reader interested in the content, to generic, vague ones? You'll see that there's definitely a correlation between the moment that HN mods change the title and the post dropping off the top frontpage spot.

What was the previous title? The current one is the same as the name of the provided link. If you don't like the title, blame the author. Mods, afaik, are just trying to follow the rule that the submission should reflect the title of the article.

The title I first saw was:

Josh Bloch Fights a LIDAR Speeding Ticket (with Science)

Which is much better than the currently edited version.

Re: The Lowdown on Lidar

#104

Post by Alupis »

taeric wrote: post #4

I confess I was expecting to not care for this. I'm not sure how any of it should be surprising, as it seemed fairly straight forward analysis of the tools. That said, this was a ridiculously fun read. More detailed than expected for some parts, and always informative. I'm glad it did not come across as anti speed detectors. Really more of a "know the limitations."

Josh Bloch is always entertaining, watch some of his video talks or read some of his books. He has a couple really good talks on GoogleTechTalks youtube channel.

Re: The Lowdown on Lidar

#105

Post by [deleted] »

Liesmith wrote: post #56
gonehome wrote: post #28

Earlier quoted context omitted.

OR it could be because speeding isn't that dangerous and the current limits on most roads don't represent what speed people actually drive at or what speed people could safely drive at. It's different on residential streets, but on freeways I think the way Germany handles it is better. Speeding tickets (and most traffic violations really) are not about safety or curbing behavior they're about generating revenue for t…

Speeding is extremely dangerous. It's ludicrous to argue otherwise. A third of crashes (including fatal crashes) involve speeding, and the faster you are driving the more likely you are to die or fatally injure another. Also, changing the speed limits on roads have been studied and it doesn't make a humongous difference. The government usually sets the speed limit at slightly lower than the average speed people actua…

[deleted]

Re: The Lowdown on Lidar

#106

Post by tedunangst »

Karunamon wrote: post #90
mnarayan01 wrote: post #80

Earlier quoted context omitted.

The "right to face your accuser" refers to witnesses. The state is _always_ the prosecutor in criminal cases (in the US, IANAL).

So what happens when you are caught breaking into a building, and the camera is evidence of your crime? This entire line of reasoning would completely destroy any kind of automated crime detection (security systems, security cameras), which is ridiculous on its face. Further, what happens when you commit a crime where there are no witnesses? People are rightfully convicted of crimes based on "things" rather than the…

In order to introduce the video as evidence, they have to put somebody on the stand who will explain how the camera works and so on. And right there is your opportunity to confront them. You can ask all sorts of questions, like when was the last time they cleaned the lenses.

Re: The Lowdown on Lidar

#107

Post by Thrymr »

growse wrote: post #22
ihaveajob wrote: post #12

Speed radars are good for speed traps, but not so great to prevent speed related incidents. They share the same fatal flaw with all other single-point speed meters: You can just slow down for a minute, while you pass by the speed trap, and then speed up for the rest of your trip. Instead, a 2-point speed meter (i.e. license plate readers every few miles, measuring time between matching reads) system is superior becau…

Possibly because the cost/benefit just isn't there. In the UK, the data shows that speeding (excessive speed for the conditions above the speed limit) is the primary cause in single digit percentage of accidents. I believe there's data from 1996 and 2007 for this, will dig it out when I'm not on mobile. If you want to spend money on accident prevention, there's much better things to target than speeding.

Even if it's not the primary cause, accidents are much more dangerous at higher speeds. It also makes reaction times shorter for avoiding other things.

Re: The Lowdown on Lidar

#108

Post by Alupis »

mortov wrote: post #61
taeric wrote: post #4

I confess I was expecting to not care for this. I'm not sure how any of it should be surprising, as it seemed fairly straight forward analysis of the tools. That said, this was a ridiculously fun read. More detailed than expected for some parts, and always informative. I'm glad it did not come across as anti speed detectors. Really more of a "know the limitations."

Often (but not always) in the UK, the laser is accompanied by video footage which shows where the beam has been trained and it is a combination of both the video and laser reading (shows on the video) which is the evidence. (all tripod mounted - so I suspect many of the issues detailed are well known). Sounds like that would give good supporting evidence for a challenge. However, traffic violations is most places are…

how can a video possibly show where a laser is pointed at from > 1,000ft away? that seems unreasonable.

Re: The Lowdown on Lidar

#109

Post by curtis »

kudu wrote: post #83

Why do HN mods keep changing the title from meaningful ones, which make the reader interested in the content, to generic, vague ones? You'll see that there's definitely a correlation between the moment that HN mods change the title and the post dropping off the top frontpage spot.

I'd really like to see more transparency when it comes to title changes. The most recent case where one of my submissions had a title change mirrors what kudu is describing here: a meaningful (and I think accurate) title changed to a generic and vague one -- followed by a rapid decline in the rate of upvotes. I think there are legitimate reasons for title changes, and I think that the Hacker News mods generally do good work. But sometimes they seem to be fixing stuff that isn't broken. I realize titles in particular can be really subjective, but that's one reason I'd like to see a comment with the old and new titles whenever a title change happens. That will allow the community to chime in when maybe the title change wasn't an improvement after all.

Re: The Lowdown on Lidar

#110

Post by goodcanadian »

ARothfusz wrote: post #6

Well, he fought with half science: he came up with a set of testable hypotheses, but didn't actually run any of the tests. I guess that's as scientific as cosmology :-)

He doesn't have to prove his innocence, he just has to convince a judge that there is reason to doubt that the LIDAR accurately reported his speed.
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