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

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.

Comments

Grace?

[Etherwalk]

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.

Re:legalism is a crap philosophy.

[houghi]

That does not mean anything if we do not know what happened or the layout of the street. Perhaps that car was speeding, but by how much? Perhaps the kid was jumping in front of the car and would have been injured anyway.

What happens in Europe is that they start making the streets in such a way that they are automatically so that you drive a lower speed. Especially in neighbourhoods where people live.

A lot of curves in the streets by placing objects in the streets., making the road more curvy and what not.

That means that the average speed will go down a lot. They just change the natural flow of traffic. and people adapt to that. Downside is that is is more expensive than placing some traffic signs and you can not generate extra income from tickets.

therefore the speed limit is invalid

[dltaylor]

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.

This speed limit is reckless

[coats]

It is very well established in the civil engineering literature how to set the speed limit for safety. Outside of exceptional circumstances the best rule is to establish the speed limit at the 85th percentile of traffic speeds (i.e., so that 85% of the traffic is going less than that limit). Unfortunately, politicians think they know better than the established engineering. They think that their wishes trump the facts.

Those who set that speed limit are acting in reckless disregard for the safety of the public. As is that CS professor--and he should know better!

Re:legalism is a crap philosophy.

[wbr1]

I live in Cville and drive through here all the time. Locust is a road that connects downtown to a highway. There are others, but this one is mostly straight and unimpeded. It is 2 lane, and largely residential. It needs to have slow speeds due to the narrowness and residential aspect. However the city classifies it as a feeder road, and does not put in slowing measures like bumps, stops or circles.

The other main roads feeding into downtown from US 250 are High to the east and Park and McIntire to the west. All three are heavily congested for various reasons. They link to other busy roads, have shopping and commercial areas, etc

I think the solution is for the city to bite the bullet and install speed bumps. It will not be a popular measure, but that is because people want to speed through there to get into or out of the downtown area. Too bad, just plan a little further ahead.