Difficulty of programming traffic lights?

Question

Is it difficult to program traffic lights so that a stream of cars will not have to stop at every other light?

Is so, is it because of a lack of resources (like city officials refusing to allocate funds for this), or is it because it is hard to estimate all the factors (speed, amount of traffic, weather conditions)?

Answer 1

In theory it is relatively simple but in most cases it doesn't work in real life. Imagine a road where the distances between the crossings/lights are not all equal. Of course it is possible to program the lights to get a continuous flow of cars - but only in *one* direction. Cars running in the oposite direction will have to stop more often!

The next problem are the cars that join in from the sides. It's not a big deal if the side streets are relatively unimportant - but in most cities there is a network of more than one main streets making things even more complicated since one of the streets will always be privileged (causing even more traffic jams on the other streets).

The whole problem is well known to theoretical mathematicians. Most of them claim, that under heavy traffic conditions a 'chaotic' program that only takes into account the relative numer of cars on the differnt roads is the optimal solution to minimize waiting time in general. There have been practical tests of this theory in several european cities and it somehow seems to be correct...

The main problem are not the traffic lights but simply too many cars on the roads.

Answer 2

No, programming and setting it up is simple in theory. I've done it on small scale. However, the lights are doing well to limit accidents at the moment. Furthermore, there are better things to spend the cash on like improving our education. Just schedule your time properly and the lights are no problem.

Answer 3

someone in a office writes a computer program that is supposed to keep traffic flowing.

but it's just that a program.

they might have a few places that have sensors that can adjust to traffic flow but most do not.

you know that some times you have to stop four times to go a 1/4 of a mile an on other days you make all those lights without having to stop.

have you ever noticed a 4 way stop that has been converted from 4 stop signs to all new street lights? instead of smooth traffic flowing your sitting at a red light with no traffic in sight for miles.

if street lights had sensors that adjusted to the traffic flow they would be better. But any thing that has moving parts is subject to breakdown and require maintenance. $

in some major cities they are using traffic cameras to monitor heavy traffic and accidents and then they change the lights to try to stop the backups.

so yes it would cost more and require more complicated equipment than what is being used now.