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The Lowdown on Lidar

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Re: The Lowdown on Lidar

#61

Post by mortov »

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 about revenue raising so anything which reduces the opportunities - like accuracy and fairness - are unlikely to get much of a look in.

edit: for clarity, it looks like this http://www.mirror.co.uk/news/uk-news/pictured-speeding-motor...

also referenced in my reply below.

Re: The Lowdown on Lidar

#62

Post by shoeless »

MichaelDickens wrote: post #52
selectodude wrote: post #29

Earlier quoted context omitted.

It's not about saving lives. It's about revenue generation.

Speed limit laws don't exist to generate revenue. They exist to disincentivize speeding. If speed limit laws didn't exist, can you imagine lawmakers saying, "We need more money. Hey, I know! Let's charge people money for driving over a certain speed!"

The manufacturers of speed cameras take a percentage, and it is a windfall for the municipality.

I live in an area where stationary speed cameras are around every corner (Montgomery Co, Maryland). I've lived here long enough to know that there's no way the county would spend money on the equipment and man power to maintain and operate that network, just to break even for the sake of safety.

Re: The Lowdown on Lidar

#63

Post by ascotan »

dmoo wrote: post #17
justinsb wrote: post #9

Can anyone tell me why speeding tickets aren't enforced with video cameras (like red-light tickets are)? It would seem to be much more accurate, much easier to enforce, and much harder to dispute. Irrespective of the rights or wrongs of speed limit laws, I do believe that consistent and efficient enforcement can only be a good thing.

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

In an effort to force people that can't afford to pay a double fine from seeking justice through the legal system? Nice.

Re: The Lowdown on Lidar

#64

Post by jpmattia »

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…

> I can't believe it's not implanted at least in all interstate freeways.

If you're around DC, there are a bunch of automated speed detectors built into the highways, and it's the same story: People slow down for the trap, and then speed up afterwards.

If you're from out of town, you're pretty well screwed because you'll be following some guy who will, out of the blue, slow down for no apparent reason.

Re: The Lowdown on Lidar

#65

Post by willyt »

justinsb wrote: post #9

Can anyone tell me why speeding tickets aren't enforced with video cameras (like red-light tickets are)? It would seem to be much more accurate, much easier to enforce, and much harder to dispute. Irrespective of the rights or wrongs of speed limit laws, I do believe that consistent and efficient enforcement can only be a good thing.

I think that's how it works in the UK. When the lidar detector catches you speeding it fires off a camera that takes 2 photos of the vehicle a set time apart. The car's progress is manually compared against a gauge painted on the road surface to see if you travelled far enough in the time between the 2 photos to have been speeding. This catches those times when a lidar detector gives a false positive.

Re: The Lowdown on Lidar

#66

Post by kaoD »

Liesmith wrote: post #58
selectodude wrote: post #29

Earlier quoted context omitted.

It's not about saving lives. It's about revenue generation.

Don't be ridiculous, If it was about revenue there would just be more toll booths.

Tolls booths are obviously about the revenue, which make the voter angry.

Not that I support his claim, just refuting yours.

Re: The Lowdown on Lidar

#67

Post by legohead »

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…

If you've traveled around the country, you've invariably come across those "speed is monitored by aircraft" signs, and what you described is how they do it (tracking how long it takes cars to go from point A to B)

Re: The Lowdown on Lidar

#68

Post by DEinspanjer »

All the talk in this thread about various forms of speed management and fines remind me of an article I read a while back about a Swedish test program that used fines from speeders as the funds for a lottery that people driving at or under the limit were entered into automatically: http://www.wired.com/2010/12/swedish-speed-camera-pays-drive...

Re: The Lowdown on Lidar

#69

Post by mortov »

Liesmith wrote: post #58
selectodude wrote: post #29

Earlier quoted context omitted.

It's not about saving lives. It's about revenue generation.

Don't be ridiculous, If it was about revenue there would just be more toll booths.

That would only be the case where people accept tolls & toll booths on roads as an acceptable thing.

Sure, they're common in Canada and the US but in some other countries they lead to years of civil disobedience, protests and eventual scrapping by newly elected governments : http://en.wikipedia.org/wiki/Skye_Bridge#Toll_controversy

Speed fines have the semi-respectibility claim of trying to reduce accidents/dangers on the road (with some validity).

Re: The Lowdown on Lidar

#70

Post by grndn »

gonehome wrote: post #28
thrownaway2424 wrote: post #16

Earlier quoted context omitted.

The fundamental reason is because drivers feel entitled to speed and most voters are drivers. People with expensive cars further believe they've paid for the privilege of violating more laws more often, and those people are also more influential in policy setting. There are lots of expressions of this fundamental reason, such as people throwing a fit about automated license plate reading in the name of privacy. But o…

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…

> the current limits on most roads don't represent what speed ... people could safely drive at.

If there's a sidewalk or any t-junctions, that's about 20mph tops. Anything faster, and you can't stop in time, plus in a collision, kinetic energy goes as the square of the speed.

For local trips, with stoplights that slow you down anyway, driving slower adds only a few extra minutes to your journey time. Personally, I'm not seeing the need to be so hurried all the time.

http://www.rospa.com/roadsafety/adviceandinformation/driving... http://blog.americansafetycouncil.com/why-speeding-is-danger...

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