May 3, 2006
We don't need no stinking traffic signals
Here's a clip of a busy intersection at some unknown foreign locale. It's a pretty busy 4-ish lane urban street with a lot of people wanting to turn left. And there's no stoplight.
Rather than being sheer chaos, this may wind up being a pretty efficient way of moving traffic under medium loads. The odds of waiting go up a lot, but the length of the wait goes down a bunch. You are almost certainly going to have to let some people pass before you can either turn or continue through the intersection, but you won't have to sit for 2 minutes while the light changes.
There have been studies done on things like this, and these intersections wind up being - counterintuitively - very safe. Why? Because they require you to pay attention and keep on your toes. Accidents at traffic lights happen when people get lazy and rely on the signal instead of looking both ways.
Still, this only works because there isn't a crushing load of traffic. As you can see, when it does get a bit heavy, there's a significant traffic jam. If the load stayed that high all the time, the efficiency of the intersection would plummet. This isn't to say that signals are bad, but that they might not be as necessary as US traffic engineers think they are, especially in urban areas.
One important function of traffic lights is to simplify the adjudication of personal injury lawsuits. That may sound cynical, but in the absence of the unequivocal directives of automated signals, it'd be far harder to demonstrate negligence, recklessness, etc. This isn't a problem, of course, in societies not yet wealthy enough to place high financial value on individual lives. But Americans are unlikely to choose to sacrifice so active an area of tort law for the sake of efficiency or even for the lives that might be saved through increased vigilance at intersections.
Posted by: Julian at May 3, 2006 9:27 AMNice as the idea of no traffic signals is...(there aren't really traffic lights or stop signs in India, where I went last summer, but nobody gets into wrecks, even though the streets are waaaay congested)...I don't think you can institute it in a society like America. People just don't get it. They're used to being lemmings.
Where I live in Florida, people think they're being all cool and European by adding things like traffic circles, but it ends up making huge traffic snarls that only slow down traffc, and make things less efficient.
My favorite *says sarcastically* is the traffic circle/stop sign/traffic light combination in the cookie cutter suburbia hell near my office--at rush hour, it turns a 2 minute trip into a 15 minute nightmare!
Neither traffic planners, nor drivers in the US can handle the freedom...
Posted by: Rebekah at May 3, 2006 10:26 AMJulian: spoken like one studying the law. And you're right: the legal class will certainly object to anything that endangers their rice bowl.
Rebekah: it's true that under heavy loads, roundabouts and non-signaled intersections break down. But under moderate and light loads, they are more efficient.
I linked this some time ago, but it's to an article discussing the theory in question. A heavily signaled intersection which always has a few deaths a year can be turned into an accident-free zone if the signals are removed. Furthermore, driver behavior is affected far more by the construction of the road - something drivers cannot ignore - than signals and signs - something drivers almost always ignore.
Posted by: ryan at May 3, 2006 11:48 AMOnly problem...Americans don't have the skill to drive in situations like that. Americans don't drive defensively or offensively...they expect everyone to drive according to the laws. So if one person does one small thing that is unexpected it causes a big accident. And also Americans for some reason like to wait in line. I have observed this in various situations. Even if there is more than one lane open they will tend to use one lane.
People in the States generally don't know what to do in unexpected situations, especially when it comes to traffic. Watch when a car brakes down in one lane on a four or five lane highway (like I-285 in Atlanta), traffic builds up for miles and miles.
Posted by: john at May 4, 2006 12:48 PM