Why does the signal include an amber and green light?
If the other lamps have bulbs in them, then I'll ask why. But the shape of the signal has to be consistent even when redundant.
EDIT: And for fun, in British Columbia, a flashing green is the same as a solid green except that it usually indicates a pedestrian operated light. I.e. it will always be green unless a pedestrian who wishes to cross pushes a button to activate it. If it is at an intersection, perpendicular traffic generally just gets a stop sign. Moreover, I recently learned that, in Ontario, a flashing green can be used to indicate an advance green. I.e. oncoming traffic is still red, so feel free to turn left.
In most jurisdictions in North America, you are meant to yield to pedestrians at all crossings. Further, there is an implied crossing at every intersection regardless of whether there are any signs or other markings. If you see a pedestrian standing on a corner, you are supposed to stop for them. Of course, what the law says and what people actually do are not always the same.
The traffic rules you describe sound… ridiculous. How is one supposed to design a free-flowing intersection if anyone may halt the traffic in any particular part at any time? In the UK, one can almost always find crossings shortly downstream of a roundabout, and pedestrian crossings at traffic lights are controlled by lights.
Flashing orange means yield (including to pedestrians, though few people are aware of that).
> But the truly puzzling thing, reports Berliner Zeitung, is that included in annual maintenance costs are not only replacement red light bulbs, but amber and green ones too.
(Also, people who are used to seeing a set of three bulbs might not recognize a single red light as being a traffic light at all.)
German traffic lights are a modular design, and ones with only two or one bulb are common. (You can stick as many modules together as you wish, or remove them)
I've only seen one-bulb versions for flashing yellow lights (which are sometimes used on crossings to indicate "pedestrians are crossing" at difficult crossings, typically when more than two roads meet and the pedestrians could easily be overlooked).
I've only seen two-light versions for pedestrians (i.e. red and green).
I think I've seen other one and two bulb versions on non-public roads (e.g. industrial sites) but that's about it. I've never seen a version with four bulbs.
And you make them sound more modular than they are: while the part containing the bulb seems to be generally modular the case containing these modules is generally fixed for a certain size. So adding or removing modules after they are deployed is not as straightforward (except maybe for temporary traffic lights).
I've actually seen the auditory clue box (whatever it's called -- the ticking thing at crossings to help blind pedestrians cross safely) replace one of the bulbs (on three-bulb lights where there is a redundant second red bulb) instead of being added below the traffic light.
There’s a traffic light for the lane straight forward.
Directly next to it is one for those turning right.
The forward light has Red, Yellow and Green, the turn lane’s light has only Yellow and Green (both with the arrow overlay).
At another one, there’s lights for busses added below or at the side of the existing light, adding one, or two modules (below or at the side).
I forgot about turn lanes (they often omit the red light when the red phase would be shared with the regular traffic light) but I've never seen bus lights. Might be a regional thing.
Woe unto the traffic-light maintainer if, should the powers that be change the light timing, the light doesn't function correctly.