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Open Source Transportation Build

Homemade Speed Trap Made By Former UVA CS Professor (cvilletomorrow.org) 582

An anonymous reader writes: Irritated by speeders in his neighborhood and frustrated with the City of Charlottesville's inability or unwillingness to enforce the speed limit, a former professor in the Computer Science department of the University of Virginia created a program in openCV to track vehicle speed on his residential neighborhood street: "You'll find that almost 85 percent of the cars going by are violators [of the neighborhood's 25mph limit]". This includes a city bus doing 34mph.
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Homemade Speed Trap Made By Former UVA CS Professor

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  • by enriquevagu ( 1026480 ) on Wednesday February 03, 2016 @06:25AM (#51428691)

    Add a link to the summary.

  • How did this submission get through review? There's no link to the source article.

    Slashdot's accepting citations from anonymous sources with no supporting evidence now?

  • by Viol8 ( 599362 ) on Wednesday February 03, 2016 @06:37AM (#51428733) Homepage

    Authorities all over the world know that people will always go a little bit over the speed limit and hence set the limits accordingly. I know this isn't what the road safety warriors want to hear but its the truth - if they want vehicles doing around 35 authorities will set the actual limit to 30 and so on.

    • Except in West Virginia. If you are not doing the speed limit or below, it is your own neck you are risking.

  • Grace? (Score:5, Informative)

    by Etherwalk ( 681268 ) on Wednesday February 03, 2016 @06:45AM (#51428749)

    There is also an unwritten "grace" that is given in many areas, where you don't ticket someone until they go 10 mph above the speed limit. To get a ticket for going 34 mph in a 25 mph zone usually means you angered a cop, you were doing it in bad weather or at some other time when it was unsafe, or you wandered into a local town's legal extortion racket--excuse me, speed trap.

    It is constitutionally questionable because of vagueness and due process, but it's still how driving works in a good part of the United States.

    • There is also an unwritten "grace" that is given in many areas, where you don't ticket someone until they go 10 mph above the speed limit. To get a ticket for going 34 mph in a 25 mph zone usually means you angered a cop,

      Yeah, that's just for selective enforcement, so they can punish brown people for being.

  • by dltaylor ( 7510 ) on Wednesday February 03, 2016 @06:49AM (#51428771)

    At least in California, other than the absolute maximum, and things like school zones, roads have to be surveyed periodically, and the speed limits must reflect the prevailing speed. If it is 85% near some higher number, including mass transit, then the limit is too low.

    • Easy solution. Just put a speed camera on the side of the road, bright and visible. Then survey the area the speed camera is pointed at.

      Still "too low"? By who's judgement? Mass swarms of human have absolutely no judgement or ability to perform risk analysis at all so they are probably the single worst source of information as to how a speed should be set. The only exception to this rule is large well built highways. Humans are good at judging risk when there's nothing unexpected that can come from a side s

  • More info? (Score:4, Interesting)

    by stevegee58 ( 1179505 ) on Wednesday February 03, 2016 @07:11AM (#51428863) Journal
    Link to original article, name of the professor please.
  • by pageauc ( 2644617 ) on Wednesday February 03, 2016 @07:27AM (#51428915)
    Last summer I wrote a python opencv program for a Raspberry Pi computer and Pi camera module. This monitors in real time. It has a lower fps due the hardware capability but does work Ok when calibrated for the distance. Here is my YouTube video https://youtu.be/eRi50BbJUro [youtu.be] github repo is here https://github.com/pageauc/mot... [github.com]. This was just done for fun after reading a forum article on the subject.
  • by overshoot ( 39700 ) on Wednesday February 03, 2016 @07:30AM (#51428921)
    Take some discarded automotive parts (coil spring, shock absorber) and fine steel cable (the original reputedly used piano wire) and run it across the road under tension a few inches above the pavement. Go over it slowly (with the speed set by the shock absorber) and you never notice it's there. Go too fast and it slices the tire right off of the rim.
    • Of course this means that driving over the cable at slow speeds causes no damage or premature wear on the tires. It's never a problem if you don't notice.
  • "85%" (Score:5, Informative)

    by Dereck1701 ( 1922824 ) on Wednesday February 03, 2016 @08:35AM (#51429195)

    "You'll find that almost 85 percent of the cars going by are violators"

    Then your speed limit is set too low, unless there is some compelling reason for it to be that low speed limits should be set by the average traffic speed (within reason). I think my state even has a law to that effect.

  • Maximum line of sight. Inclination, curve, drainage, presence of sidewalk, distance to intersection, distance to driveway, populaton of children, proximity to school, width, apparent width.

    Then setup a traffic cone at various detail points in the road and measure the distance to the cone to make cars stop. You just need a cone, adjustable speed limit indicator, and a tape measure.

  • On my way to Canal Winchester on OH-674, I’d pass through a small section of Lithopolis, where the speed limit inexplicably drops to 45mph. It’s a well-known speed trap, for the locals, so the village makes(or made) money mostly from visitors. One time, an Ohio state legislator was caught in that speed trap, and there was a bit of a smack-down that ensued. But that wasn’t the beginning of the end of Lithopolis. That started when they closed the only interesting thing in the whole villa

    • I remember when New Rome, Ohio was dissolved for similar reasons. I wonder how widespread it is for states to dissolve speed trap towns.
  • The project he's working on now is a Raspberry PI that automatically shouts "Get off my lawn!" whenever it detects someone under 18 encroaching on his property.
  • by Jim Sadler ( 3430529 ) on Wednesday February 03, 2016 @10:43AM (#51430119)
    If he goes to the PD and files a complaint with the recorded evidence the PD has no choice other than writing a ticket for every violation. It is handy for bicyclists to know this as with a cam mounted on the handlebars, one can get the plate number of every car that tries to pass you in the same lane or in a no passing zone.

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