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Around the web
1. The Promise (and Limits) of Neuroeconomics
2. Remember Fabio Rojas, our most frequent guest blogger? Now he is blogging "full-time," on orgtheory.net.
3. How does the traffic light know when a car is there? I used to think "the weight of the car," but I was wrong.
Posted by Tyler Cowen on September 16, 2006 at 05:36 PM in Web/Tech | Permalink
Comments
*g* You get to be very alert for these inductive loops if you do a lot of biking. Bikes can sometimes, but not always, trigger them if you ride over them just right. It can be very irritating on low-traffic roads when there's not a car liable to come along and save you quickly, and especially on low-traffic side streets when you need to turn onto or cross a high-traffic main street.
Posted by: Andromeda at Sep 16, 2006 6:48:52 PM
Alex & Tyler,
As a daily reader of MR, I want to thank you for all of the time you put into this blog. It is an incredibly useful and insightful source.
Not sure if you've seen this website, but www.bookmooch.com may be more proof of markets for everything. The design of the website, which involves swapping books with strangers from all over the would, relies on weak system of "points" and reciprical sharing of used books. I've now been a member for about a month and have been moderately impressed. People seem to respond by sending books rather quickly (if in the US, it takes about a week). The problem right now is that there is a limited pool of books available. While the Book Mooch model probably won't work for new books, it is a decent model for obtaining classics and widely read books.
Posted by: Niall at Sep 16, 2006 7:33:59 PM
I always assumed it was weight too.
I am usually very thankful for those sensors, until some nitwitt ahead of me stops short or pulls up too far to trigger them, and I end up sitting through 2 or more cycles until I give up and go another way.
Posted by: BillWallace at Sep 16, 2006 8:17:01 PM
Once you know what to look for, you can trip the ones designed to switch when enough traffic piles up (the inductor is about 5-10 car lengths from the light, but it doesn't know that you stopped with "a good, safe" distance between the next car up.
Posted by: nelsonal at Sep 17, 2006 12:00:50 AM
Readers might also be interested in the article in the current New Yorker on neuroeconomics:
http://www.newyorker.com/fact/content/articles/060918fa_fact
Just in case.
Posted by: Pienso at Sep 17, 2006 11:04:09 AM
Newer signals are using a camera-based detector that uses image recognition software to figure out if a vehicle is waiting at the signal. This solves the problem of motorcycles (which often don't have enough steel to trip an inductor) and allows the road to be resurfaced without needing to replace the inductive loop... allegedly the costs are about the same, once you factor in the resurfacing/reinstallation expenses of loops.
Posted by: Chris Lawrence at Sep 18, 2006 12:43:21 AM
??
...rather surprising that educated persons really thought there was a 'weight-scale' triggering all those traffic lights.
Such simple technology is a widespread mystery ??
[" We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology "]
(-- Carl Sagan)
Posted by: Darlton at Sep 18, 2006 6:58:38 AM
There's just such a switch on a side street heading out of harvard square onto memorial drive--a street I used all the time in grad school--but the construction crew cut the square too far forward and it crept into the cross walk. Therefore the light didn't change (litterally, it wasn't on a timer most of the day) without someone driving into the cross walk... When I was second in line behind some tourist I would have to get out of my car, tell them to pull forward 5 feet, and they'd look at my like I was crazy. But then the light would change instantly...
Posted by: adam at Sep 18, 2006 9:18:14 AM
