Citizen uses OpenCV to track speeders near his home • Hacker News Board

Re: Citizen uses OpenCV to track speeders near his home

#61

Post by jstanley » Tue, Feb 02, 2016, 3:04 PM UTC

SixSigma wrote: post #11

pc86 wrote: post #6

> At 4:27 p.m. last Wednesday, the system caught a Route 11 city bus doing 34 mph. Which isn't even fast enough to get a ticket from local police. In my state (which is not Virginia, and it will vary everywhere), local police are prohibited from using radar and need to use an actual stopwatch to track your speed. Obviously very error prone, and they're supposed to basically give you 10 mph leeway - meaning on that ro…

10 MPH ? That's ridiculous, elsewhere it is 10% because that is the legal requirement of the speedometer

The 10% margin of error for a speedometer only applies in one direction: they're allowed to say you're going faster than you really are by up to 10%, but they're never allowed to say you're going slower than you really are (in England).

Re: Citizen uses OpenCV to track speeders near his home

#62

Post by jld89 » Tue, Feb 02, 2016, 3:05 PM UTC

Another problem in my opinion is the fact that the metrics in the US are in imperial measures. 30 mph is 50 kph, it's about pure numbers.

50 is higher than 30 so common sense tells you that you are going faster. Even if it is not true. There is a subconscious reaction of people to numbers, no matter the metrics.

Re: Citizen uses OpenCV to track speeders near his home

#63

Post by mikeash » Tue, Feb 02, 2016, 3:05 PM UTC

Someone1234 wrote: post #44

gus_massa wrote: post #31

I'll copy a very interesting comment by Anton Largiader http://www.cvilletomorrow.org/news/article/22908-locust-aven... > One very interesting approach I have seen overseas is a traffic light that turns red if you are speeding as you approach it. It's incredibly effective; instant feedback on your behavior, and immediate loss of any time you gained by speeding. No ticket, unless you run the light. Drivers quickly con…

I like that idea but I do worry about it causing rear-end collisions. In an ideal world drivers wouldn't speed and they also wouldn't tailgate, but in the world we currently occupy both are extremely common (even amongst law enforcement). So while this would act to reduce speeding, the unpredictability may increase accidents and it is definitely going to reduce traffic flow.

Rear end collisions like this tend to be pretty benign. For example, one of the arguments against red light cameras is that they actually increase the number of accidents. However, they also increase safety. How? Because while they increase the number of rear end collisions, they decrease the number of side impact collisions, which are much more deadly. Net result: more bent metal, less bent flesh.

I'd also be surprised if speed-sensing lights really increased collisions much. They still go through a full yellow before turning red. They are only more unpredictable if you know the light's cycle time, watched it turn green, and are carefully timing it so you could otherwise predict it.

Re: Citizen uses OpenCV to track speeders near his home

#64

Post by danso » Tue, Feb 02, 2016, 3:05 PM UTC

specialdragon wrote: post #39

In summary, he's made a speed camera and is now proposing the use of it to his local council. Are speed cameras not as ubiquitous in the USA as over here in the UK?

They are common, but not ubiquitous by any means. They're usually used in prominent intersections/stretches in which speeding is observed to be common.

Re: Citizen uses OpenCV to track speeders near his home

#65

Post by jrowley » Tue, Feb 02, 2016, 3:05 PM UTC

I was assuming from the title that he was going to actually track down the speeders using OCR on their license plate. Cool read though

Re: Citizen uses OpenCV to track speeders near his home

#66

Post by oneeyedpigeon » Tue, Feb 02, 2016, 3:05 PM UTC

Spooky23 wrote: post #4

Welcome to the age of nitpicking busybodies. Next month, he'll have a facial recognition system for dog walkers who fail to curb their dog.

If you are incapable of driving in a manner that doesn't cause undue risk to human life, then a camera highlighting that should be the least of your worries.

Re: Citizen uses OpenCV to track speeders near his home

#67

Post by dpflan » Tue, Feb 02, 2016, 3:05 PM UTC

"Locust (Avenue) is classified as a collector road, which means the city prefers not to install stop signs or speed humps. The city is working on alternatives that could include painting new parking spaces, installing planters or narrowing lanes."

The road by (unintentional) design seems promotes higher traffic speeds by having few impediments; it is also intersects a highway (BVP 250 via Google Maps), which I suspect could influence drivers near the highway to be increasing speeds or maintaining speeds they had while on the highway. I'd like to know where the speeding is occurring in relation to proximity to the highway.

This made me want to explore how speed limits are set.

I found this "Methods and Practices for Setting Speed Limits: An Informational Report" by the U.S. Department of Transportation: Federal Highway Administration.

- http://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa12004/ - http://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa12004/fhw...

Re: Citizen uses OpenCV to track speeders near his home

#68

Post by heywire » Tue, Feb 02, 2016, 3:06 PM UTC

dsfyu404ed wrote: post #57

chucksmash wrote: post #29

Earlier quoted context omitted.

The guideline I was taught was FWIW, I've never been pulled when I was following those guidelines (driving in GA + SC).

One of the rules of thumb taught to cops is "over by five, let 'em drive, over by 10, get out your pen"

The variation I always heard (as a driver, not a police officer) was, "Five, you're fine, ten, you're mine!"

Re: Citizen uses OpenCV to track speeders near his home

#69

Post by pc86 » Tue, Feb 02, 2016, 3:06 PM UTC

notacoward wrote: post #46

pc86 wrote: post #8

Earlier quoted context omitted.

Red light cameras increase rear-end collisions as well as injury because people would rather lock up their brakes one car length before the intersection than get a ticket. I haven't seen any information on the effect of cameras at merging sites, though.

I wasn't suggesting anything that triggers red lights or leads directly to a citation. Just gathering the data would often be useful, to drive design of intersections and allocation of other resources in a quantitative way. Also, if people aren't maintaining a safe distance from the car in front of them, then that's useful information too. So is video of people illegally using their celphones while driving, which thi…

Well if you rear end someone you will be cited for it 99% of the time.

But surely your answer to something that quantifiably increases injury rates isn't "who cares it's their own fault" is it?

But since you asked for a citation: http://bfy.tw/4343

Re: Citizen uses OpenCV to track speeders near his home

#70

Post by danso » Tue, Feb 02, 2016, 3:07 PM UTC

wott wrote: post #22

Is it allowed in the USA for an individual to film public space?

Yes. This is usually part of First Amendment arguments, particularly when police and photographers clash over the right to document police arrests that happen in the public.