Slashdot Mirror
Traffic Light Switcher Makes Critics See Red
An anonymous reader writes "According to a Yahoo/Washington Post article: 'It sounds like a suffering commuter's dream come true: a dashboard device that changes red traffic lights to green at the touch of a button.
Police, fire and rescue vehicles have had access to such equipment for years, but now the devices are becoming available to ordinary motorists
thanks to advances in technology and a little help from the Internet. Safety advocates are outraged, and news accounts in Michigan last week
led to politicians there seeking a ban on the gadgets'." Update: 11/06 02:25 GMT by S : A previous Slashdot story mentions the device, though not the Michigan legislature's subsequent ire.
As the article states, most cities and counties use the Opticon system by 3M. This system has two components, an encoded flash reciever, and a radio reciever. In order to pre-empt the light, you had to have a valid encoded flasher, and the encoded radio signal. There is no nation-wide standard for the pre-emting devices, so each locality sets up its own code. Good luck trying to us one of these black boxes to trip signals, it won't work 99.99% of the time.
I worked on the traffic signal system in a central california town, and we had 3 different codes: 1 for fire/police, 1 for ambulances, and one for maintenance work. Each time a signal was pre-empted, it was logged at the signal control center downtown. I worked with a guy who had a maintenance encoded flasher on his truck. It was kinda fun cruising through town, never hitting a green, but we didn't do it very often.
I think the black boxes they are selling are just for people dumb enough to think they work.
It's tough, but if everyone cleaned up their driving habits, everyone would be home 5 or 10 minutes earlier rather than just the poor drivers getting home 2 to 3 minutes earlier.
\begin{game theoretic rambling}
This is a classic example of prisoner's dilemma, where individual welfare is pitted against the common good. Either way, a driver is better off if he acts greedily: If most drivers cooperate with each other, then the greedy driver takes advantage and gets home before the cooperating drivers. If almost nobody cooperates, then one must be a greedy driver, or be taken advantage of.
The big question here is what should a driver do to make commuting the least painful, and there's no simple answer. There are many possible strategies:
1. Always be greedy -- that way you're never the sucker.
2. Never be greedy (Golden Rule) -- that way you're looking out for the common good, and if most other people do the same, then the relatively few greedy jerks out there won't cause too much trouble.
3. Only be greedy in retaliation to another's greed (tit for tat) -- can work well, but can lead to feuds of reciprocal retaliation between two parties.
What will work best? Who knows? Many studies have been done on this with two-player games, with tit-for-tat being the clear winner. Traffic, of course is a multiplayer game, so who knows? My guess is that it would depend on the current traffic conditions -- if you're driving with a bunch of jerks, you have to be a bit greedy, otherwise, go with strategy (2).
\end{game theoretic rambling}