Yellow Light Phase on Traffic Lights

[Bub]

     I have noticed, over my 9+ months of playing simutrans that on traffic lights the phases go as follows ie.: Green, Red, Green...
     My question is, where is the yellow light? If there are 3 lights on a traffic light, how come the yellow light isn't used??

[Spartanis]

I wondered about that, but then , i think the Simutrans Council Workers ran out of Amber Light Bulbs

[IgorEliezer]

how come the yellow light isn't used?

The question is: how could yellow light help the player? What would yellow light affect, control or change in Simutrans?

[Leva]

What if the yellow light would allow next one or two cars go trough the intersection?

When theres green light all cars coming to the traffic lights can drive trough. The same way as it is now.
Then the lights would change into yellow light and it would allow next two cars that are 1 or 2 tiles away from the lights to drive trough.
And then the cars behind of these two cars would have to stop because of the red light.

I'm not sure would it help the player much but at least you would know when the green is going to turn red.

[VS]

I'm not sure would it help the player much but at least you would know when the green is going to turn red.

That's the most sensible reason so far, IMHO. And it is only eye candy...

[Bub]

     I think yellow lights would be great, as explained by Leva, but how many seconds would the yellow light phase be?