The Lowdown on Lidar • Hacker News Board

Re: The Lowdown on Lidar

#91

Post by gknoy » Thu, Jul 31, 2014, 5:15 PM UTC

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"?

Re: The Lowdown on Lidar

#92

Post by saosebastiao » Thu, Jul 31, 2014, 5:15 PM UTC

quux wrote: post #87

saosebastiao wrote: post #45

Earlier quoted context omitted.

I have yet to get into an accident, but I actively avoid walking across several streets in Seattle because of a combination of entitlement thinking (This road is mine because I'm in a car!), and pervasive speeding. I'm not the only one...I recently found out almost nobody on my side of a local road will cross the road due the same problem. The road, therefore, has become a barrier to commerce and has split a communit…

There aren't any traffic lights and crosswalks on this street?

There are some crosswalks, 8 blocks away from each other. No lights for at least a mile. In WA state, every intersection is automatically a legal crosswalk with pedestrian right of way (unless marked with a "No Pedestrian Crossing" sign), but the lack of enforcement combined with the high speeds makes that right of way effectively meaningless.

Re: The Lowdown on Lidar

#93

Post by Karunamon » Thu, Jul 31, 2014, 5:15 PM UTC

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.

Agreed - the original title, about a guy beating a LIDAR ticket, was much more descriptive than this headline, which effectively says "This article is about LIDAR".

Re: The Lowdown on Lidar

#94

Post by diminoten » Thu, Jul 31, 2014, 5:15 PM UTC

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.

Re: The Lowdown on Lidar

#95

Post by koenigdavidmj » Thu, Jul 31, 2014, 5:15 PM UTC

kudu wrote: post #24

dmoo wrote: post #17

Earlier quoted context omitted.

In Ireland we have a system where you can contest any of these automated fines in court. The problem is that the fines and penalty points double should you contest and lose. http://en.wikipedia.org/wiki/Penalty_points_in_Ireland

How is that even legal? It seems like it would infringe on the requirement of due process anywhere in the world.

That's just a more formalized version of a plea bargain. (Whether plea bargains are just as much a due process violation is not part of my post.)

Re: The Lowdown on Lidar

#96

Post by jstalin » Thu, Jul 31, 2014, 5:18 PM UTC

In Michigan, a speeding ticket is a civil infraction, not a criminal offense, so the legal standard is preponderance of the evidence, not beyond a reasonable doubt, as the slide deck says. I suspect it's the same in California.

Re: The Lowdown on Lidar

#97

Post by diminoten » Thu, Jul 31, 2014, 5:19 PM UTC

ape4 wrote: post #76

Don't Google's self driving cars use LIDAR.

They probably take all of these things into account.

If they didn't, I suspect Google's self driving cars wouldn't use LIDAR.

Re: The Lowdown on Lidar

#98

Post by goodcanadian » Thu, Jul 31, 2014, 5:19 PM UTC

grndn wrote: post #78

reitanqild wrote: post #59

Earlier quoted context omitted.

A Dutch engineer once told me (back before 2004 I guess ) that they once raised the speed limit on the roads in Netherlands only to find average speed decreased. His explanation IIRC was that 1. once people broke the limit it didnt matter how much and 2. when speed limits felt more correct more people respected them. I'd love to know if anyone has any pointers to research on this as around here speed limits are weird…

I used to live in Los Angeles. On the freeways, the speed limit was 55mph but I read once that the actual average speed was around 17mph. My (unscientific) theory is that with higher speed limits, you get more traffic waves, and people try to change lanes more often, causing delays. If the speed limit on LA freeways was only 25mph, I would hope that people would chill out and the traffic would flow more smoothly, res…

Be careful with your average speeds. I often drive in excess of 70mph on the (65mph limit) freeway in LA, and I am far from the fastest car. The key difference is that I don't drive in rush hour. A 25mph speed limit would be absurd.

Re: The Lowdown on Lidar

#99

Post by jaredmcateer » Thu, Jul 31, 2014, 5:19 PM UTC

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.

I agree it was stupid of the author to not have realized his presentation to a captive audience would be linked to the public and made it a more compelling title for casual consumption

Re: The Lowdown on Lidar

#100

Post by timthorn » Thu, Jul 31, 2014, 5:21 PM UTC

ghkbrew wrote: post #73

timthorn wrote: post #57

Earlier quoted context omitted.

In practice, they're actually very good for improving traffic flow on busy roads - because almost everyone is driving at the same speed, jams just don't form in the same way. The utilitarian argument for them is very strong.

Do you have evidence to back up that claim? It seems counterintuitive that slowing down the top few percent fastest drivers would improve traffic. If there's enough traffic to cause congestion wouldn't they be stuck behind slower drivers anyway?

Anecdotal evidence, but it also makes intuitive sense if you consider that vehicles travelling at a range of speeds and particularly changing lanes to overtake the slower drivers is effectively a turbulent flow. If that flow can be smoothed, as a body it travels faster.