Study: Chicago red light cameras provide few safety benefits(chicagotribune.com)
chicagotribune.com
Study: Chicago red light cameras provide few safety benefits
http://www.chicagotribune.com/news/watchdog/redlight/ct-red-light-camera-safety-met-20141219-story.html#page=1
36 comments
Atlanta had red light cameras for about a year, until enough people complained and they made a mandatory minimum yellow light duration for lights with cameras. By the next year, none of the cameras were operational anymore, the company that was running them said they weren't making enough money off the program so they shut it down.
I would say this is the perfect example of the need for taxation.
The best solution for the people involved shifting money from the people to an entity that installs and maintains those cameras. So, to get there, you need some method for moving money from the people to said entity.
Let's say those cameras decrease property damage/hospital costs/costs of lost time by an amount of X, what is against taxation of the total costs of that are smaller than X?
The best solution for the people involved shifting money from the people to an entity that installs and maintains those cameras. So, to get there, you need some method for moving money from the people to said entity.
Let's say those cameras decrease property damage/hospital costs/costs of lost time by an amount of X, what is against taxation of the total costs of that are smaller than X?
> […] this is something Chicago was guilty of […]
I’m guessing this was a problem before red-light cameras:
— What? What did I do?
— You failed to stop at a red signal.
— The light was yellow, sir.
Elwood Blues and Trooper Daniel, Blues Brothers (1980)
I’m guessing this was a problem before red-light cameras:
— What? What did I do?
— You failed to stop at a red signal.
— The light was yellow, sir.
Elwood Blues and Trooper Daniel, Blues Brothers (1980)
Was it ever actually about safety? The whole point of it seems to be just to create another revenue stream for thousands of corrupt local governments all across the country.
Some were, there are two intersections in Georgia, one is Windy Hill Road and I forget the other but it is in Gwinn ette county where they had real numbers to show the crashes went down. Windy Hill was just damn nasty and its a big intersection. I still prefer those where traffic is only going one direction.
Still I do think many are in place only for revenue, much like speed limit cameras. I would rather see red light cameras than speed limit cameras, however I want the later to come only under specific circumstances with full public accounting. I think if they really want to sell us on safety it should all go to charity.
Still I do think many are in place only for revenue, much like speed limit cameras. I would rather see red light cameras than speed limit cameras, however I want the later to come only under specific circumstances with full public accounting. I think if they really want to sell us on safety it should all go to charity.
Something I've seen a lot in Europe is speed cameras in places that have a specific good reason for people to slow down. Several seconds before encountering the camera is a sign with the speed limit and a camera icon or the word "radar". The purpose isn't to issue tickets, but to get people to slow down for the dangerous section of road.
Some are there because they need to be, some aren't. In my country most of them aren't there to keep you safe but to have a revenue stream.
I know a couple of signals that are there to just make people slow down, and they work even if a lot of us know that there's no radar there.
I know a couple of signals that are there to just make people slow down, and they work even if a lot of us know that there's no radar there.
Most speed/red light camera's aren't actually owned or operated by the government. They are run by private companies who get the right from the government for a cut of the revenue. No it wasn't ever about safety but make no mistake it is a private for profit company pushing these things on everyone they just happen to dupe the government with a promise of a taste of the revenue.
The point was to create a new revenue stream. It seems more like the company that installs them markets heavily in that regard. Part of their installation process is a 'recommendation' that the yellow lights be reduced in time as low as possible.
The other massively understated thing about Chicago's red light cameras is that Chicago, compared to other areas with similar or even much lower traffic volumes, has very few left turn lanes, and even fewer left turn arrows when they are there. As a result, the general population is habituated to only being able to turn left at the last second on a yellow signal, which complicates the short yellow timings even more.
The problem is that there are lots of other choices to make an intersection safer than cameras.
Generally, the psychology of the timing matters. Most of the intersections that I see people crash aggressively are busy intersections and have lights that take forever to cycle. So, there is a huge time penalty for missing the light (something like 4-5 minutes).
If you cycle the light faster, it may let fewer cars through, but it tamps down the aggressiveness with which people are willing to crash the light.
Generally, the psychology of the timing matters. Most of the intersections that I see people crash aggressively are busy intersections and have lights that take forever to cycle. So, there is a huge time penalty for missing the light (something like 4-5 minutes).
If you cycle the light faster, it may let fewer cars through, but it tamps down the aggressiveness with which people are willing to crash the light.
I don't know how common these lights are around the world (I have never seen them in the US but have not been EVERYWHERE), but in China I regularly saw lights that also had a timer to the side of it counting down so the change from yellow -> red was more easily expectable. I think this would work rather well if we were all really concerned with safety.
I'm not sure where I read it, may have been an article posted on HN a while ago, but just the opposite actually happens. I think it was where a countdown timer is present for the pedestrians, but since drivers can see them they tend to speed up if the light is about to change. Which causes more accidents, esp with pedestrians.
> since drivers can see them they tend to speed up if the light is about to change.
This is easily solved. For example, intersection just outside my window [1] has LED timers next to traffic lights, but the countdown is blanked (turned off) for the last five seconds, not to encourage reckless speeding.
The blanking appears to work just fine, judging by the way the traffic flows. I pass the intersection daily, both by car and on foot.
[1] in a mid sized city in Poland
This is easily solved. For example, intersection just outside my window [1] has LED timers next to traffic lights, but the countdown is blanked (turned off) for the last five seconds, not to encourage reckless speeding.
The blanking appears to work just fine, judging by the way the traffic flows. I pass the intersection daily, both by car and on foot.
[1] in a mid sized city in Poland
We also have that in my country, but I don't think this really helps while driving as I usually glimpse at the lights and keep my attention to the road, I usually don't read the timer at all. We also have very short yellow lights so you either have to kick down the accelerator or brake hard.
In almost 3000 words, this article didn't see fit to mention the effect on pedestrian/vehicle collisions. I wonder if this is due to lack of data? I would check the Chicago Open Data Portal (https://data.cityofchicago.org/) but it's down right now for maintenance!
This article seems to make a point that we should get rid of the red light cameras because they increase rear crashes.
Ignoring for a moment that T-bone crashes are likely to produce much more severe injuries than someone crumpling up the rear of another car, this should suggest that we instead need ways to monitor motorists for keeping proper distance and attentiveness.
The solution can't be to stop monitoring for one offense because it causes incompetent motorists to cause more offenses of another sort.
Ignoring for a moment that T-bone crashes are likely to produce much more severe injuries than someone crumpling up the rear of another car, this should suggest that we instead need ways to monitor motorists for keeping proper distance and attentiveness.
The solution can't be to stop monitoring for one offense because it causes incompetent motorists to cause more offenses of another sort.
The solution is well known - increase yellow light times. [0] It reduces accidents (both rear and t-bone) and violations.
But it's crap for generating more revenue, which is quite often seen as more important.
[0] http://www.motorists.org/red-light-cameras/timing-myths
But it's crap for generating more revenue, which is quite often seen as more important.
[0] http://www.motorists.org/red-light-cameras/timing-myths
I think it's both. Increase times and also enforce red-light cameras --but within reason. Where I live, at some intersections there aren't always dedicated LH turn lanes, so people have to wait till oncoming traffic has a large enough gap to make the left. Often times, the only time left to make the left is to wait for the yellow... and the 3 or four cars behind have an option of going through a red light or waiting again for a yield on green... In this situation, people have little option but going through a red (or possibly taking a more circuitous route).
That said, for the most part, I feel red light cameras are a racket.
That said, for the most part, I feel red light cameras are a racket.
[deleted]
Are we talking about people who would normally run the light then realize there's a camera? I don't know why the existence of cameras should increase accidents if people weren't trying to beat the light.
Several studies have shown that cities installing red-light cameras "coincidentally" have ridiculously short yellow lights. The yellow light should last long enough for anyone already committed to going through the green light to safely finish doing so. Otherwise, drivers in the intersection have to accelerate to avoid having the light turn red with them still in the intersection, and drivers not yet in the intersection have to slam on the brakes and effectively treat yellow as red.
Why is the traffic light relevant when you are in the intersection? In Germany it doesn't matter anymore once you enter the intersection, mostly since you just cannot see it. It seems absurd to me that the traffic light would still be applicable at that point. To me the rule then is basically for everyone to pay attention to what everyone else is doing.
Which is exactly how it should work, and normally does, in the absence of a red-light camera.
Gonna need a citation on that T-bone decrease, buddy. Sorry.
"Scheinfeld said in an interview last week that the city's safety claims are based on "more basic," nonscientific comparisons of crash statistics"
"Scheinfeld said in an interview last week that the city's safety claims are based on "more basic," nonscientific comparisons of crash statistics"
The citation is given in this article, which says there's a 15% decrease, and not the 47% of the nonscientific comparisons:
> "But the Tribune study, which accounted for declining accident rates in recent years as well as other confounding factors, found cameras reduced right-angle crashes that caused injuries by just 15 percent."
It also includes the analysis that revelation calls for (the balance of severity and incidence rate):
> "The economic analysis examined the extent to which the increase in rear-end crashes negates the benefits for decreased right-angle crashes," the 2005 study concluded. "There was indeed a modest aggregate crash cost benefit of RLC systems."
which is why "The Tribune researchers also suggested that Chicago could reap much better results if it shut down about 40 percent of its cameras, located in about 75 intersections throughout the city where crash rates were lower to begin with."
> "But the Tribune study, which accounted for declining accident rates in recent years as well as other confounding factors, found cameras reduced right-angle crashes that caused injuries by just 15 percent."
It also includes the analysis that revelation calls for (the balance of severity and incidence rate):
> "The economic analysis examined the extent to which the increase in rear-end crashes negates the benefits for decreased right-angle crashes," the 2005 study concluded. "There was indeed a modest aggregate crash cost benefit of RLC systems."
which is why "The Tribune researchers also suggested that Chicago could reap much better results if it shut down about 40 percent of its cameras, located in about 75 intersections throughout the city where crash rates were lower to begin with."
[deleted]
Is the actual study available anywhere? I am wary of trusting a journalists interpretation of data, especially when it comes in an article that gives the impression "this study our paper funded demonstrates exactly what we thought it would!"
While I can't give you a link to this study, I can say that it supports and extends work I did as part of a graduate stats class for my MBA - we looked at the data that was publicly available at the time and it was clear that the cameras weren't making a statistically significant difference at most intersections... So, just another piece of anecdotal evidence but if you really want it I can try to dig up our work.
Retrospectively, I guess we should have been better about sharing our findings.
Retrospectively, I guess we should have been better about sharing our findings.
Phoenix has red light cameras as well, because of numerous scofflaws from south of the border. I have no idea how effective they are, but there are still a lot of horrible accidents.
To reduce if not halt such incidents, we should simply build crossing gates as at railroad crossings. When the light is turning yellow, a gate lowers, with flashing red lights and clanging bells. When the light cycles to green, the gate lifts. Problem solved.
Alternatively, hire more traffic cops to enforce the laws. It costs money, but the carnage on the roads calls for some kind of a real fix and not just a cosmetic patch like cameras that merely bring in more revenue.
To reduce if not halt such incidents, we should simply build crossing gates as at railroad crossings. When the light is turning yellow, a gate lowers, with flashing red lights and clanging bells. When the light cycles to green, the gate lifts. Problem solved.
Alternatively, hire more traffic cops to enforce the laws. It costs money, but the carnage on the roads calls for some kind of a real fix and not just a cosmetic patch like cameras that merely bring in more revenue.
[deleted]
Url changed from http://arstechnica.com/tech-policy/2014/12/major-chicago-stu..., which points to this.
The new URL seems paywalled. Possibly one could use some user-agent setting to see it, but I just read the the original article instead.
Unfortunately there is a tradeoff between two of HN's preferences: for original sources and accessible ones. In cases like the current one, where an article is clearly definitive and not so paywalled that none of the standard tricks can get at it, the preference for original sources wins. It's not a great situation but I know of no satisfying fixes for it.
It is. While not optimal, I just go to google, search for the URL and click on th top link. With referrer set to google, most newspapers show you their content.
Bookmarklets, referer spoofing and other improvements left as exercise for the reader.
Bookmarklets, referer spoofing and other improvements left as exercise for the reader.
A better solution would be enforcing a sane minimum yellow light timing on camera intersections. Shortening the yellow to the point where the normal traffic sometimes brakes hard to avoid entering the now yellow, soon to be red camera intersection is the reason for this increase in rear-ends.
Per the article, this is something Chicago was guilty of, in addition to placing the cameras in areas that had no problematic history of accidents.
The real problem with these things is that they are used as another way to milk money out of the populace, rather than as a way to modify behaviour and improve safety.
These cameras ( and short lights ) are something that really really annoy me as a motorcyclist. I can stop fast any time but the SUV-clad soccer mom texting behind me probably wont. I sometimes find myself dropping a gear and hammering through a yellow I could easily stop for because of this.
/rant