I'm a huge fan of putting information where people need it, when they need it. That's why I was very excited when cities started to put displays on the pedestrian crossing signals counting down until the traffic light was going to change.
The problem comes down to: different people walk at different speeds. So, in order to ensure that someone could or couldn't make it across during the light the timing of the pedestrian signals had to cater to the lowest common denominator. Those who knew they were faster than this rate would find themselves guessing on whether they could cross or not, often getting it wrong. These incorrect judgements would cause congestion while the pedestrian walkways cleared, and that makes the lights less efficient.
The countdown timer combats this problem by giving the pedestrian more information about when the light is going to change. They can then make better judgements about whether there is enough time for them to cross. Or, if they're in a hurry, whether running across the street would help. All in all, it increases the amount of information passed to the user by the traffic light in a situation where a pedestrian can use the information to make a better choice. Whoo! Hoo!
Now the lights are being reconfigured so that the count down timer does not hit zero when the light changes. It hits zero at some arbitrary time before then, and that arbitrary time is different depending on the person who set up the light. Effectively the light is lying to the user about its state. This makes the information effectively useless as people start to ignore an inconsistently reliable source. We're back at where we started.
I'm unsure why so many cities have started doing this. Perhaps there was an article on it in "City Manager Today." But, if I was to guess I would say that it was to combat what I call "The Asshole Factor." This is a factor that needs to be applied into any situation involving groups of humans. In that group there are likely to be a few assholes. These are the people who, when all the cars are merging well, quickly pull ahead and try to get three cars closer in line. The people who trade shares of stock to vapor corporations and rob people of their retirement savings. And, I imagine, people who use the extra information given by the lights to be even bigger assholes -- perhaps even causing car accidents.
So the city managers adjust the traffic lights so that they lie to everyone, to try and make the assholes behave (which never works; they're assholes). The net result is that no one believes in the data that they're being given and the light timers become information noise in our overloaded world.
posted Sep 27, 2007 | permanent link
