How effective are red light cameras?

MSNBC posted an article about red light cameras, describing how many cities are taking them down. Why? Because the cameras are too effective: people learn where the cameras are and stop running the red lights. According to the article, the city of Dallas recently turned off a quarter of its red light cameras because it couldn’t justify the cost of running them. Other cities have had similar experiences.

Not surprisingly, the cameras’ effectiveness at reducing accidents is inconclusive. According to a study released in 2005 by the Federal Highway Administration, intersections with red light cameras get about 15% more rear-end crashes than they would have without the cameras. It seems as though drivers know that the cameras are there and will brake aggressively to avoid running the light. However, the study also reports a 25% decrease in T-bone crashes, with about 16% fewer injuries. Overall, the study reports no appreciable difference in the number of accidents, and an almost 5% decrease in injuries.

All told, the FHA study concluded that red light cameras give, at best, a “modest aggregate crash-cost benefit.”

And then there are opponents’ claims that, even if the cameras provided a huge safety benefit, that still doesn’t justify the systematic violation of drivers’ constitutional rights. I tend to lean towards this belief myself.

However, it’s rather amusing that cities are finding it increasingly difficult to justify the cost of red light cameras because drivers are running fewer red lights. One wonders if, were the cameras provided a demonstrable safety benefit, whether cities would continue operating them at a loss. It’s probably a good thing for city public relations that the negligible safety benefit means that they can turn the cameras off without a loud public outcry.

Comment Spam

I get a moderate amount of comment spam here on the blog. Fortunately, WordPress lets me moderate comments before they’re posted, and it’s pretty easy to separate the signal from the noise. Most of the comment spam is pointers to pharmacy web sites or links to porn sites. Some, though, are really random. Like the one I got today: “Sorry, but what is kimerikas? Jane.” That was the entire comment. Always willing to learn something new, I searched Google for “kimerikas,” and got about 900 hits. I didn’t look at all of the hits, but the few pages I did look at all contained identical comments. If anybody knows what kimerikas is, please let me know.

Another comment spam I got recently was for a piece of software that will post trackbacks to multiple blogs. Yes, you got that right: spam offering a spam generator.

It continues to amaze me that spam in all forms is still prevalent. Is there any research to indicate that spam is profitable? I’m sure it’s profitable for the big outfits that send spam on behalf of other people (i.e. they get paid to flood my email with trash), but do the people who pay these outfits actually see a return on their spam investments? With most major mail servers’ frontline filters throwing out the vast majority of spam, and the few stragglers being easy to identify and delete manually, how can anybody make money trying to advertise this way?

Fried Lamp

The lamp that sits behind my desk and that provides the majority of the illumination when I’m working here started blinking infrequently the other night. At first I thought it was the normal power fluctuations we get here from time to time, but then I began hearing what sounded like something shorting out. I reached to turn off the lamp, and the steel base was very hot to the touch. Obviously, I unplugged the lamp.

I tore into it this evening, figuring it was just a fried switch. The switch is fried, no doubt, but I also found this:

The black wire in this connector comes from the AC power source. The red wire goes to the switch.

When I disassembled the lamp, the top of this connector was touching the metal base. At first I thought that over time a piece of metal inside the connector had rubbed a hole in the clear plastic insulation and came into contact with the lamp base, causing a short. But when I cut off the burned part, there was no metal sticking out. I can only conclude that the switch shorted out and the resulting heat traveled down the 4″ red wire to this connector, melting the insulation and allowing current to arc between the base and these two wires.

Looking more closely at the switch, I see molded into the back the words, INCANDESCENT ONLY, but I don’t see anything that gives a current rating. The fixture in question is a halogen torchiere floor lamp with a 300W bulb. These lamps are said by some to be a fire hazard, although those that I have meet the safety guidelines published by the CPSC.

I can’t say for certain that this switch is original equipment, as I obtained the lamp from a former employer when our office was closed. As far as I can recall, nobody there ever replaced the switch (it would have been out of character), and I certainly hadn’t taken the thing apart before.

I have two other lamps of this type. One of them had a bad switch when I got it, and the other has been working in my living room for at least 10 years. You can bet I’ll be looking into that switch soon, though.

Is it common for the switches in these things to burn out? [Note added later: It’s a three-position switch with off, low, and high settings. I almost always used the ‘low’ setting.]

The bike doesn’t make the cyclist

In How to succeed at astrophotography¬†— or at anything else, Michael Covington points out that the key to success in almost anything is knowledge, not stuff:

All too often, people buy gadgets, string them together, and assume that the machinery ought to know how to take the pictures. It doesn’t!

And they respond by buying yet more expensive gadgets, which they understand even less, and getting even more frustrated.

When I was big into mountain biking (before I bought a road bike, and before I injured my shoulder), my friend Jason and I were out at one of the most difficult trails in the area one day and ran across another cyclist. Walter joined up with us, and it wasn’t too long before we could tell that he wasn’t up to the challenge of this particular trail.

The problem with accepting another rider in the group is that etiquette demands that you stay together as a group. So we went slower and spent a lot of time waiting as Walter caught his breath or walked his bike over especially difficult parts of the trail.

Walter was a friendly enough guy, and quite impressed with his equipment. As well he should have been! In stock condition, his bike cost more than Jason’s and mine put together, and over the course of a few months he’d added the latest and greatest everything. After a half dozen or so anecdotes about how he went to the shop and had this or that added to his bike, Jason turned around and said, “Walter, sounds to me like you should spend more time on the trail and less time in the shop.”

I often see Walter’s spiritual twins when I’m out on the road. They’ll have the latest and greatest road gear–bikes that cost two or three times as much as mine (and mine wasn’t cheap)–but have difficulty climbing even the most modest of hills, or slow to a crawl when faced with the typical south wind. I understand that not everybody is a nut about cycling like I am, but when I talk to these people on the road their conversations are all about how better tires, lighter wheels, or some other mechanical improvement will allow them to ride farther and faster. Unlike my friend Jason, I don’t point out the obvious: that if they spent more time riding and less time worrying about their equipment, they’ll be astounded by their improvement. I just say, “have a good ride,” and pedal away on my own.

Get good equipment, but get just the basics at first. Learn to ride well, and to ride as well as your equipment will allow. Then upgrade–when you have the skill, knowledge, and fitness to take advantage of the better equipment.

More Windows Vista bits

Windows Vista (and Windows Server 2008) have formalized the idea of a “public” directory–a directory on your computer where you can share files with other users. In previous versions, you had to create a folder yourself (often called “Public”) and share it. Vista has a special folder called “Public”, and subfolders named “Public Documents,” “Public Downloads,” “Public Music,” etc. If you enable public folder sharing, then files in those directories are accessible by anybody who can locate your computer on the network.

It can be a bit confusing, though. Here’s a screen shot of Windows Explorer showing the Public folder on my machine:

Looking at that, you’d expect the UNC path to my “Public Downloads” directory to be “\\JIMM\Public\Public Downloads”. But if you try it, you’ll quickly find that the path does not exist. Where, then, is it?

If you click in the address bar of Windows Explorer (image below), you’ll see that the local path to my “Public Downloads” directory is “C:\Users\Public\Downloads”.

Since the main Public directory is \\JIMM\Public (although you won’t see C:\Users\Public if you select the Public directory and then click in the address bar), then it follows that the Downloads directory would be \\JIMM\Public\Downloads. And that’s what it is.

it’s kind of confusing that the real directory name is something different from what’s shown in Windows Explorer. But I’m happy that the names don’t have embedded spaces. Filenames with embedded spaces make working with command line tools difficult.

I gotta see this!

I noticed this sign as I was walking by Wendy’s yesterday at lunch, so I went in to have a look. They told me that the fish only works the breakfast shift. I’ll have to stop by some morning, ’cause I just gotta see this.



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