[ryanjmo]

I came across a light like this once and noted it. After some thought though I realized that it actually makes perfect sense. The goal of the light is to never let people go straight and people can only turn on a green arrow. It is the only logical output for this goal as far as I can tell. If it were just a red arrow and a green arrow, without a full red people may think they can go straight, because there is no light preventing them explicitly. It's pretty funny.

[kolinko]

This is not it. There must be signs accompanying the light saying that you cannot go straight.

Without the signs, someone would simply arrive at the intersection and wait god-knows-how long for it to turn green, until they gave up and went right :)

The reason for the light is that according to regulations, at an intersection, every road leading to it has to have lights. You cannot have three streets with lights, and one with just a sign saying "stop and yield".

[ryanjmo]

It is definitely true that a sign was improve the drivers understanding and be helpful, however the light is still necessary. Stop and yield is not sufficient... that puts the decision of when to turn on the driver of the car, instead of being dictated by the light as is the desired behavior...

I still see this as the only way to communicate correctly the rules of the intersection. And yes, add a sign as well to let people know they can only turn right.

[rootlocus]

Except, If I see a red light, I expect it to turn green eventually. On the other hand, If I see a sign telling me I'm only allowed to turn right, I know exactly what's going on. Explicit is better than implicit.

[ryanjmo]

Whether or not there is a sign, you still need the light.. A sign is not sufficient as it puts the decision of when to turn on the driver of the car, instead of being dictated by the light as is the desired behavior...

[a_bonobo]

Couldn't you combine a STOP sign with one of those 'turn only right' signs, like this one? http://l7.alamy.com/zooms/95a9489a7d8b4c418cb6cfd3b6753295/r...

[kolinko]

The street also has that (well, a triangle "yield, no stop necessary" sign).

The thing is, in Europe, you have priorities in traffic - first the lights, when those are off/unavailable - the signs, and finally "the one on the right goes first".

The rationale behind this intersection is that you need all the vehicles obeying the same set of rules. So you can't have one car approaching the intersection obeying the signs (because no lights on that road), and another car obeying the traffic lights.

[FabHK]

FWIW, police signalling manually > traffic light > traffic signs > "right before left"

[mc32]

In that case a flashing yellow right arrow would make more sense than a solid red light.

[ThePadawan]

Don't quote me on this, but I think drivers are allowed to drive on a flashing yellow light without coming to a full stop, while this red light requires drivers to come to a stop.

[ygra]

Flashing yellow means yield, indeed. However, if the traffic lights are off the signs take precedence which in this case also just say yield. The red light with the green arrow is a hack in that it allows the intersection to work as intended, but the Stop part of it probably is not strictly necessary here.

[ryanjmo]

A stop with an arrow is not sufficient as it puts the decision of when to turn on the driver of the car, instead of being dictated by the light as is the desired behavior...

[usrusr]

What if you really want to go straight and take the red light as a hint that it will eventually be green? 28 years of blocking the road?

According to the maintenance mentioned in the original link, the other colors are still there...

(Google streetview shows it too, but the picture dates back from when the red light was still youthful twenty years young)