Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Citizen uses OpenCV to track speeders near his home

cvilletomorrow.org

Post reply on HN
Print view View original

111–120 of 138 posts

Re: Citizen uses OpenCV to track speeders near his home

#111

Post by peatmoss »

webjprgm wrote: post #80

I don't know if people share this opinion, but to me speeding is due to the inadequacy and inconsistency of speed limits. Near my home there is a major thoroughfare with a 35 MPH speed limit. It has no homes facing the road, just a few fenced backyards some fair distance away but mostly it has farms, ponds, and golf courses. People regularly go 40-50 MPH down this road. Another major road that crosses this one has a…

> Then there's also the fact that city planners never manage to build sufficient roads until the current ones are overcrowded.

As a planner, I always find this sentiment amusing. The only thing less popular than being stuck in traffic, is the use of eminent domain that would be required to pave ever larger percentages of our urban land.

Planners can't expand roadways into the 5th dimension. Roads require land--a lot of it in fact. Also, it's not like planners don't anticipate that congestion will be increasing if demand for vehicle travel and population also increase.

Lastly, the prevailing wisdom in planning is that "widening roads to combat congestion is like loosening your belt to combat obesity." There's a popular press book that talks about how increasing roadway capacity can paradoxically worsen traffic: https://books.google.com/books?id=ckLcxEb5tM8C&hl=en

Re: Citizen uses OpenCV to track speeders near his home

#112

Post by athenot »

jurassic wrote: post #49

Some commenters here are commenting as if speeding is some petty thing that doesn't matter. Speeding kills. Something as small as 10 miles over a 30mph may mean a doubling in fatality rate for pedestrians and bicyclists. One source: https://www.aaafoundation.org/sites/default/files/2011Pedest...

The issue in residential areas is the time and distance it takes to come to a full stop. Speed of travel is a proxy measure for those two values.

A good awareness test to try (on a barren road out of the city and away from any traffic) is to slam on your brakes at various speeds, and in various conditions (dry/wet/pouring), and observe how much time it takes for you to come to a stop. Bonus points if you're still in your own lane when you arrived to that complete stop.

Re: Citizen uses OpenCV to track speeders near his home

#113

Post by bryanlarsen »

drzaiusapelord wrote: post #98
bryanlarsen wrote: post #97

Earlier quoted context omitted.

You omitted the fact that it reduced injuries by 15% from side-swipe collisions. The Time omitted the fact that side-swipe collisions tend to have more serious injuries than rear-end collisions. They also failed to mention that red light cameras reduce the number of pedestrian and bicycle collisions.

The article certainly mentions the holistic view here: "Taken together, the study shows a statistically insignificant increase of injuries by 5%." Time's source is the Tribune: http://www.chicagotribune.com/news/watchdog/redlight/ct-red-... Emanuel has credited the cameras for a 47 percent reduction in dangerous right-angle, or "T-bone," crashes. But the Tribune study, which accounted for declining accident rates in…

Still no mention of injury severity.

Re: Citizen uses OpenCV to track speeders near his home

#114

Post by ryandrake »

JoeAltmaier wrote: post #82
ryandrake wrote: post #76

Earlier quoted context omitted.

> Reynolds and neighbor Bruce Odell will make a presentation on the software to the council Monday night. It's not just a neat tech hobby--this is a busybody pitching what amounts to ubiquitous rule-enforcement to the local government.

Yeah I'd say that too - except its speed limits in residential neighborhoods. We're not talking about what color they're painting their front doors. We're talking injuring people. All sorts of desperate measures are taken to try to control this - speed bumps, no-car zones, cameras. This seems cheaper and maybe more effective than all that?

What's even cheaper is not wasting money on "all sorts of desperate measures" and instead, crack down severely on the people actually out there injuring people with their cars (which is also against the law).

Re: Citizen uses OpenCV to track speeders near his home

#115

Post by sorenjan »

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…

One solution is dynamic speed bumps that measure the speed of vehicles, and then lowers if the vehicle is speeding.

https://www.youtube.com/watch?v=eRHphB-YqN8

https://www.youtube.com/watch?v=KxpvwKiOpag

Re: Citizen uses OpenCV to track speeders near his home

#116

Post by jdmichal »

athenot wrote: post #112
jurassic wrote: post #49

Some commenters here are commenting as if speeding is some petty thing that doesn't matter. Speeding kills. Something as small as 10 miles over a 30mph may mean a doubling in fatality rate for pedestrians and bicyclists. One source: https://www.aaafoundation.org/sites/default/files/2011Pedest...

The issue in residential areas is the time and distance it takes to come to a full stop. Speed of travel is a proxy measure for those two values. A good awareness test to try (on a barren road out of the city and away from any traffic) is to slam on your brakes at various speeds, and in various conditions (dry/wet/pouring), and observe how much time it takes for you to come to a stop. Bonus points if you're still in…

Alternatively, look for local racing tracks that would be amenable to you trying this during non-operational hours.

Re: Citizen uses OpenCV to track speeders near his home

#117

Post by oxplot »

athenot wrote: post #112
jurassic wrote: post #49

Some commenters here are commenting as if speeding is some petty thing that doesn't matter. Speeding kills. Something as small as 10 miles over a 30mph may mean a doubling in fatality rate for pedestrians and bicyclists. One source: https://www.aaafoundation.org/sites/default/files/2011Pedest...

The issue in residential areas is the time and distance it takes to come to a full stop. Speed of travel is a proxy measure for those two values. A good awareness test to try (on a barren road out of the city and away from any traffic) is to slam on your brakes at various speeds, and in various conditions (dry/wet/pouring), and observe how much time it takes for you to come to a stop. Bonus points if you're still in…

To add to that, and perhaps more importantly, is human brain's constant reaction time and tunneling of the vision at higher speeds. The former means that you'll be travelling a longer distance before being able to react to something like seeing a pedestrian entering the street.

The latter narrows your peripheral vision such that looking straight, you won't be able to detect movements on the footpath and crossing streets.

EDIT: A famous commercial by NSW government [1] about the difference of 5km/h.

[1]: https://www.youtube.com/watch?v=h9VWF1DXQ8s

Re: Citizen uses OpenCV to track speeders near his home

#118

Post by mdip »

__luke wrote: post #21

Let's open source it!

Completely agree - does anyone know if there are similar open source projects around this? I already have an RPi camera setup for this exactly purpose, but I estimate speed manually (I've measured distance between two visible points on the camera and do a quick calculation as the front bumper passes each point).

I've had it on my "list of side projects" to solve this problem with OpenCV, but haven't gotten enough "Tuits" to get it done, yet since the camera footage has been enough to get me a police car in front of my house monitoring speed. My cousin is a cop in my county and he's indicated that the spot is basically a "ticket-writing factory" -- they don't even bother with cars going 5-10 over since there are so many going 15+ and parking right in front of my house, across the street, puts the cop in a spot where he's not able to be noticed until the car is too close to slow down enough to avoid a ticket.

For a while, the spot was even marked as a speed trap on Waze (not sure if it still is, nor whether or not I was the one who marked it :), but I haven't looked in a while).

When I get it done, I'll be sure to post the complete code along with a blog post on how to set it up, but if there's anything already out there that could get me close, I'd love to know about it.

Re: Citizen uses OpenCV to track speeders near his home

#119

Post by GordonS »

SlashmanX wrote: post #79
masklinn wrote: post #24

A pretty common sight around here (western europe) which seems to work pretty well are dynamic reminder signs: electronic signposts with a speed radar, which simply displays your speed in green if you're under the limit, orange if you're a bit over and blinking red if you're way over (using fairly bright led arrays so it's visible in most conditions) Anecdotally, it seems to work pretty well, drivers do slow down whe…

In Ireland there's a few of these types near school types which have pictures of kids crossing the road and if you're going under the limit it says "Thank you for not speeding", if you're over the limit it displays "Slow Down!" in red

Plenty of this type in Scotland too

Re: Citizen uses OpenCV to track speeders near his home

#120

Post by GordonS »

sorenjan wrote: post #115
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…

One solution is dynamic speed bumps that measure the speed of vehicles, and then lowers if the vehicle is speeding. https://www.youtube.com/watch?v=eRHphB-YqN8 https://www.youtube.com/watch?v=KxpvwKiOpag

Great way to damage your suspension
Post reply on HN