German traffic light stays red for 28 years (2015) | Hacker News Reader

German traffic light stays red for 28 years (2015)

thelocal.de

374 pointscurtis295 comments

I know this light personally. I live there. It is no problem for the casual driver, as Dresden is one of those rare german towns with US "Rechtsabbieger" rules. You may turn right even with red lights. And the german law clearly states if one entries to a crossing has lights, all others have to get lights also. This is the only case in Germany where this law makes no sense.

But the best is the last sentence: They do change all the green and yellow light bulbs also in their regular maintenance schedule. The justification goes like this: Bulbs mostly wear due to hours in usage, yes. Red and Yellow are not used, so should not wear, and thus should not be replaced. But hours can not be the only cause for problems, and while we are there and there's a budget for replacement, we'll do it all together. Not really a just technical justification, just a practical one.

We do the same in software also all the time. There are two principles: 1. Make minimal changes to cause only minimal effect. 2. Harmonize your changes to avoid unnecessary asymmetries. They went with 2. You can fight the system, or you can live with it. In this case there is no reason to rock the boat.

[Update:] The lawful alternative would have been to close this crossing for the Ziegelstraße into the Güntzstraße. People would have protested over this sillyness. And Dresden has enough budget surplus to do such things. In fact Dresden was very lucky in its real-estate deals, where they sold all of their old residential apartment complexes to a US company Fortress for billions: http://www.spiegel.de/wirtschaft/milliardendeal-dresden-verk... Normally such deals turn out bad and unprofitable, but in this case not. Both parties are happy.

> Dresden is one of those rare german towns with US "Rechtsabbieger" rules

If it's anything like the picture, the reason right turns are allowed is the green arrow (it roughly translates to "when red, right turns are allowed if you don't interfere with other traffic"). I strongly doubt random towns in Germany can bypass the StVO (the laws which govern public roads).

EDIT: To clarify, I was born in Cologne, which is on the opposite of Germany, and green right arrows exist here as well and they are part of the material you learn for taking a driving exam.

Dresden is not allowed to bypass the StVO, so they had to put up this crazy light, yes.

But the Rechtsabbieger "Grünpfeil" is also in the StVO § 37 Abs. 2 Nr. 1 Satz 8 bis 10 https://de.wikipedia.org/wiki/Gr%C3%BCnpfeil

History: The old DDR came up with this Grünpfeil (turn on red) law. During the Wiedervereinigung it was "agreed on", that this law can persist for max. one more year, 1991. But based on huge civil protests on silly law reforms (same for abortion and women rights which where more advances in the east), Germany kept this exception, and even some old ex-BRD towns introduced it since.

I believe Dresden had most of the existing 2.500 Grünpfeil signs in Germany, but in the meantime the west has caught up, and there are now 5.000 such signs.

Grünpfeile were really new in West Germany after the reunification. My brother told an anecdote from when he once drove through Hamburg and saw a Grünpfeil there, which had a sign below it explaining how it worked (something like: "Grüner Pfeil = Stoppschild für Rechtsabbieger", "green arrow = stop sign for right-turning drivers"). He quipped that this was probably the only traffic sign ever to come with its own manual.

Unlike in France, where for some reason a lot of symbolic signs come with text instructions on a separate sign:

http://s3.freefoto.com/images/41/03/41_03_88_web.jpg

(English: "Give way")

The same is true in the United States to a certain extent, though the instructions are a bit more complicated usually. The Yield sign and the Stop sign will have the relevant text within them, but below those signs you will have instructions for the given intersection, especially with stop signs:

"4 Way" or "All Way" -- Indicates that every entrance to the intersection has a stop sign. I understand all way stops are either uncommon or unheard of in Europe.

"Cross Traffic Does Not Stop" - often used with "Two Way" stop

"Traffic from the left/right does not stop" -- often used when one direction is coming off a signaled light or crossing railroad tracks, or other cases when traffic from one direction needs to continue to flow to prevent a backup that could be dangerous.

Crosswalk signal instructions regulatory sign -- https://commons.wikimedia.org/wiki/File:MUTCD_R10-3b.svg

Judging by what I've seen in photographs, the instructions on US signs often either state what should be obvious or are unnecessarily complicated (often because there are unnecessary exceptions other countries would simply omit).

Actually that's a really nice way for people to learn what traffic signs mean, way before they start studying for a driving license.

I don't own a driver's license either. I just pick this stuff up. Sometimes I ask my current driver what a certain sign on the road means.

Or you could teach it in school. In Germany we had bicycle excursions in school, including a mock "cycling license exam" where we drove on a test track with various road signs and traffic lights.

Is this one ever used? http://radyzezivota.cz/wp-content/uploads/Dopl%C5%88kov%C3%A...

This is the normal sign, yes. But in some towns (esp. Dresden, but now everywhere) we have simplier ones, a green arrow without light. You are allowed to turn right on red then, if traffic allows. Similar to the US.

https://ais.badische-zeitung.de/piece/00/bb/82/9b/12288667.j...

Yes. The difference is that the lighted version does not require stopping (because it's only lit when there is no cross-traffic anyway), whereas the static sign does require a stop before turning.

This. I was actually unaware of this distinction before studying for the driver's license and always assumed the sign was just a stylised version of the light to save energy.

Also worth of note: when traffic lights are active they always take precedence over static signs which in turn take precedence over road markings (which themselves take precedence over road layout). The green arrow sign is special in this regard because the rules for traffic lights explicitly take it into account -- otherwise the red light would always trump the sign because of precedence rules.

Not in this form, no. The green arrow light would be required to be next to the other green light in this case (in Germany at least). But those do exist, yes.

So IOW it's not so much that Dresden is one of those cities with American laws but that they make more use of that German (originally East German) law that is these days commonly made use of throughout all parts of Germany even though Dresden still features them more prominently?

Sorry for nitpicking but your first post read like Dresden had special traffic laws and green arrows were rare outside a handful of cities (plus AIUI the green arrow has slightly stronger implications in the US).

Yes, I was unclear.

fwiw, in the US you can turn right on red unless there is a sign saying you can't... I've never seen a green arrow sign. Sometimes there are green arrow lights that say you have a protected right turn.

Not in New York City, where you may not unless specifically marked so.

good to know... how likely are you to get pulled over for turning right on red illegally, but safely?

All the time. It's a surefire way of pulling over someone from out of town. My first ever memory of being pulled over was visiting NYC. My dad was driving and got pulled over. The cop said: "no right on red in New York City!" - a phrase that is now burned into my memory.

Occasionally it will be screamed at you by pedestrians in Manhattan when you edge out and block the crosswalk.

You are 7 likely...

But also importantly, it is allowed in New York state, just not the city. Very weird.

NYC should secede from NYS.

An aquantance of mine wrote a peice of software that looks at satelite pictures of Prague at night and tells the city which street lights are out, so they don't have to use a "regular replacement schedual" but only replace the bulbs that need it. Could the same thing not be done using red-light cameras and stop lights?

Hey, that's a good idea - exception catching for traffic lights

Replacing a traffic light after it already failed is too late.

Not in London. Nearly every day I see a new failed one. There is usually redundancy tho

That seems like the right approach. The traffic light has a backup bulb and alerts when one burns out. I mean, cars can tell when a bulb is out, right? Why shouldn't traffic lights.

Actually it's even simpler than that, just have a minimum of 2 lights per direction of travel.

So if one fails, a bulb burns out, one gets destroyed in a storm, or anything else happens, there will be at least one full backup.

Having automated outage reporting still makes sense though. It keeps you from having a guy that's paid to check every light in the city manually. And since your lights are on a city-wide network (they are, right?), then adding outage reporting should be a feasible thing.

It might or might not. This is a costing exercise where you need the understand the objective and cost factors.

If you have a strong requirement to avoid failure, proactive replacement let's you optimize the unit cost of replacement because you can fully utilize the crews and have no wastage.

If you dispatch reactively, you either have people sitting around waiting for light bulbs to burn out or lightbulb replacement pulls crews off of other work, impacting schedules.

...or you could hire contractors when you need to do bulb replacement? Then you have full utilization while you're replacing bulbs, no one is idling on your payroll while you're not, and no one gets pulled from their existing work to do replacement.

... and the external contractor who you're pushing all that risk on will charge you appropriately.

Sure, but they only receive the full amount of the risk you lose if you are their only client. They're still cheaper than either solution I responded to.

That's an option too, but is more complex and less deterministic.

The key assumption is you want low/no downtime. The problem you have is negotiating SLA penalties are difficult to get right for organizations like cities and getting good metrics are tough.

The other thing, especially with government contracting where RFPs are extremely difficult to change after the fact without getting contracts disputed by the losers is that the contractor will add risk premiums for penalties.

In the UK the device managing the junction can already detect most failed lamps, it's common in safety applications to have paired filaments, so when one fails the other still works but you can detect the problem. People selling a city devices to manage their traffic offer the feature of the city being informed about failed lamps. But, that costs money and saving money is important in most places, so they'd rather wait for motorists to report a failed junction and repair it after the fact versus paying extra to solve it first.

As things move to LEDs it hardly matters anyway, a correctly engineered LED lamp doesn't suddenly fail like filament lamps, it just gets sort of dim gradually, so a regular schedule (e.g. replace all the LED lamps every 5 years) is the correct way to deal with it. Cheap consumer-grade LED modules sometimes fail suddenly due to over-heating or badly made electricals but the road maintenance people probably aren't buying unlabelled stuff off eBay so they're unlikely to have that problem.

> But hours can not be the only cause for problems, and while we are there and there's a budget for replacement, we'll do it all together.

what does it matter if the green and yellow bulbs are broken? They'll never be turned on.

I think the point is the bulbs are cheaper than the (a) cost of developing, deploying and tracking a one-off maintenance protocol change and (b) risk the instructions are applied to the wrong intersection.

This. And they rules may change, and someone might decide to turn them on someday. They are prepared then :)

It should be obvious if the light doesn't have ANY yellow or green bulb that they shouldn't be changed.

Usually we teach people to not try to be clever when applying checklists. More often than not the "obvious" thing to do can have fatal consequences.

Or maybe the last person forgot, or they were stolen, or whatever. You'd probably have to report that and waste the time of a bunch of people.

surely it is illegal to put up a traffic signal without working bulbs.

If the traffic lights on that intersection are off or go into that mode due to other reasons you'd have a yellow blinking light.

What happens when someone from somewhere else comes to this light? Do you see tourists stuck here?

I think for most tourists the green arrow next to the red light should be suggestive enough.

Tourists don't come that way. It's very small residential street, turning into a big street with lots of confusing signs and disallowed directions. For me the much worse problem is the other way, coming down the Güntzstraße to the Elbe. The whole crossing is a real city planning nightmare, and I worked in city planning for some years.

The streetview image posted by advisedwang shows there's also a white-on-blue "must turn right" sign at that junction. This ought to make it clear that you shouldn't wait there to go straight.

Except that the traffic light takes precedence over the sign and thus the sign has no effect whatsoever as long as the traffic light is active.

No, it would take precedence if it had an arrow painted on it, but as it's just a traffic sign, it only controls entry into the intersection, not where you can go.

Hey, so just to clear things up, because nobody seems to have mentioned it: Is there a sign indicating that there are only right turns allowed? (White angled arrow pointing right on blue background)

As a driver approaching this particular crossing while seeing I'm only allowed to turn right I'm not sure I'd ever notice the light staying red indefinitely.

There is such a sign, but it's irrelevant as long as the traffic light is active so you can just ignore it. The whole intersection is also built in a way that you can really only go right as there is nowhere to go straight ahead or even left. And you surely would notice the green arrow sign next to the red light and act accordingly.

> This is the only case in Germany where this law makes no sense.

Actually, there are two more permanently red lights in Dresden alone. They are mentioned at the end of this Video: https://www.ndr.de/fernsehen/sendungen/extra_3/Realer-Irrsin...

Geil

Is there a more complete overview of this traffic situation somewhere? I still find the reasoning a bit hard to understand.

I understand that from this road, you can only ever turn right, and can do so at all times, so there's no need for a traffic light, except that it legally needs to have one because other roads at the junction need traffic lights for other reasons.

So what are the other roads here? Clearly it has to be more than just the Ziegelstraße and the Güntzstraße.

I think this is it: https://goo.gl/maps/uLpY8kjjJFw

Ah this makes the whole thing so much clearer. Thank you. (Why couldn't the article have this?)

https://www.google.no/maps/@51.0539102,13.7575856,3a,75y,78....

so could someone just sit at the stop light to just annoy the other german drivers and police?

I also do remember somewhat fondly when Dresden still had actual police officers regulating traffic by hand. It's been some time since I left Dresden and I don't remember the crossings. Oh, and the frequent power outages..

Okay, the law requires a signal light at that intersection. Okay, the light is always red because reasons.

What I don't understand is why the 3 light red/yellow/green signal unit has never been changed to a 1 light red-only unit.

Perhaps because it wouldn't "look like" a traffic light and so would be potentially confusing ("Wait, do I have to stop for that, or can I just turn?").

I know I've seen single lamp traffic lights before.

Like this one....

https://c1.staticflickr.com/3/2041/2234314943_bdcd95d800_b.j...

Those come with a "stop" sign as well and are usually seen on high speed highways as a way to get drivers' attention long before the sign comes into view. This intersection has a yield sign. A blinking red "stop" and a yield can't go together can they?

A blinking single bulb red light is the same as a regular 3 bulb traffic light red light, with the exception the 1 bulb red light on/off is programmed with a shorter periodicity. Take a blinking red and make it a solid red. Obviously, they took a 3 bulb traffic light where the red light should be turned off periodically and programmed it to show continuous red. A continuous red light on a 3 bulb red/green/yellow traffic light is abnormal behavior for that type of traffic sign.

You could have mentioned, that the traffic light doesn't exist anymore: http://www.faz.net/aktuell/gesellschaft/ewiges-rot-an-dresdn...

I feel like there's an analogy to software in this story. Someone put in a hack that, while ugly, works. I'm sure many city planners over the years have looked at it and thought it should be fixed. But when the current solution is working, taking the time to do the necessary testing to ensure that a new, cleaner solution works would be painful. So, 30 years later, the hack is still in place.

I know I've come across the software equivalent of this many times in my life as a developer. "Hmm...that's a really odd way of doing that, I should refactor this. But I need to write a bunch of tests for this since the original developer didn't write any. And am I really thinking through all the possible use cases properly? Even if I am, this is now a 3-day estimate, which means it will probably take 5 days, and all to "fix" something that's technically working. That's a lot of risk/time commitment for very little payout. Maybe I should just leave it be and move on to a project that's better setup to succeed."

Yep...makes total sense that this light still exists. Still doesn't explain why they replace the green and amber bulbs though...

It is more like "convention over configuration". In fact, it isn't a hack. It is the simple applyance of putting elements in a system, because of a contract.

Another good analogy in software would be UX and style guides. You'd like the user to have a consistent experience.

The replacement is like running a cron job to do some stuff and forget to check if it makes sense. It can be done better, but on the other hand, it's less complicated this way (and never change a running system).

This one red light has been removed btw. The street is a dead end towards the intersection now. But you can find another one near Wasaplatz.

One more evidence that "convention over configuration" principle should be avoided :)

I think it's evidence to the contrary. We only know how much one street light cost; we don't know (from this article) how effective the overall system that manages the whole country is. I can bet that because of these rules it's much more effective then a system where every single streetlight has to be considered and configured by a bureaucrat who makes an individual decision.

When extra3 had a segment on these red lights in their "Der alltägliche Irrsinn" ("Everyday madness") series, they said that there were three such lights in Dresden. I only know the one at Wasaplatz heading into Oskarstraße. Let's see if it survives the upcoming redesign of Wasaplatz this year.

No eng. code of conduct overrides "it works, don't touch".

The traffic light: https://www.google.com/maps/@51.0539102,13.7575856,3a,75y,71...

That light is totally redundant. The white-on-blue right arrow as well as the solid line in the middle of the street already mandate that only right turning is allowed there.

Except when it's snowing.

You would need at least a stop sign, as the green arrow mandates you to stop.

I've seen cases where the 'stop' sign is just a red circle, and then it changes to a green arrow pointing to the right when you're free to go.

But a stop sign at an intersection with traffic lights is only to be used as a 'backup' for when the traffic lights fail, so it wouldn't be in force?

Except you cannot have static signs from one direction, where the other directions have traffic signals.

Someone else suggested a great programmer would have changed the rules, but that would have just made the rules more complicated.

This solution is neat, because it keeps the basic rules simple while solving the problem. And to most people, they will never notice it is a problem.

Until an attacker comes and "parks" in front of the red light blocking all the traffic. There is no legal obligation to keep moving.

The law tends to address this in various ways. I don't know how German law does it, but usually there is a fairly exact description of what stopping for a traffic signal entails (e.g., the driver has to be present in the vehicle). Also most jurisdictions have a catch-all law that prohibits dangerous behaviour in traffic.

So yes, there probably is a legal obligation to keep moving. If you went there and stood in front of the light for an hour a friendly but stern police officer will — legally, and within his mandate — instruct you to move along.

The charge is usually "public nuisance" or the local jurisdictional equivalent.

In case anyone is unfamiliar with the concept of public nuisance as a crime. It's pretty simple, "things that cause significant enough trouble for other people". Its the common sense escape hatch option for law enforcement being unable to see any other crime.

I would guess that it would be "Behinderung des Straßenverkehrs" (obstruction of traffic).

They could solve this problem by turning it green every now and then, though.

There is, though. General red with a specific green (the arrow pointing to the right) means you can stop, but once a car behind you wants to turn right, you need to turn right too in order to keep traffic flowing.

> Except you cannot have static signs from one direction, where the other directions have traffic signals.

I don't know about such a rule. There are some intersections in Germany where there are red and orange lights, but no green for e.g. just one direction. At such a place, when no light is on, rules according to the static signs apply, while other directions still show some light. So what you're saying doesn't hold at least temporarily there.

> This solution is neat

I don't think so. Someone unfamiliar with the place might think the light will turn eventually green, even if it's unclear where one could go if it did. It will at least cause confusion and unnecessarily draw attention away from actual traffic. And of course there's the maintenance and power cost.

I was just in Dresden over the summer and stayed at a hostel only 2 km from there! To think I got to witness such a feat of engineering... thanks so much for posting

Google Maps still pleasantly surprises me. Their 3D view of the area is quite stunning to see in a browser. https://www.google.com/maps/@51.055998,13.7573524,222a,20y,1...

The new 3D view is amazing. I've wasted hours playing with it.

Does anyone know if the implementation was ever explained?

I'm pretty sure they just took the Bing Maps "Bird's Eye view" concept and then applied their existing Google Earth 3D-mapping tech to it. Most of what was exclusively in Earth years ago has been slowly integrated into Maps.

Well, fair enough, but then I'm interested in the Google Earth 3D-mapping tech :)

Except that it isn't there anymore. It got removed last year: http://www.faz.net/aktuell/gesellschaft/ewiges-rot-an-dresdn...

Wow, that moving IBM ad in the background is ridiculously annoying.

This is a light in Ft. Walton Beach Florida. I took a picture of it years ago because I thought it was funny. It's on 35mm film in a box somewhere.... (the linked image is not mine).

http://www.funnysigns.net/files/never-turns-green.jpg

You'd think they'd just put up a sign that says "right turn only" or similar.

That's quite unusual for an intersection that visually can be traversed also straight ahead to be right-turn only from one direction. There are such signs (209-20), or arrows on the lane, but I'd imagine people to heed a stop light more than such signage (purely from experience, many drivers ignore such signs, and even those that don't often don't adhere to the rules by not using turn signals).

Edit: Now that I've looked at the traffic light on Google StreetView, that right-turn only sign is also there. But of course, traffic lights take precedence when they exist. The intersection is also marked in a way to really discourage going straight (or left), but I'd still guess with only signs there'd be a few people who actually tried doing that.

I grew up in Fort Walton Beach! Spent 20 years there. Now live in Seattle. I've seen this!

Where is this? I go to Destin a few times a year. Usually visit Fort Walton and all over. Can't figure out where it is.

There was one somewhere in Atlanta (where my sister lived for a while, I'm from the UK and was visiting) which is exactly the same; I made her drive back so I could take a picture of it as I thought no-one would believe me (this was in 1998, IIRC). At least after reading the comments in this thread it makes some sense now.

This article is from 2015 and noone seems to have mentioned yet that the light got removed in 2016: http://www.faz.net/aktuell/gesellschaft/ewiges-rot-an-dresdn...

When I was about 15 years old, a friend tried to convince me a traffic light in front of his house was always green. I never believed him. Fast forward 15 years later. I moved to an apartment, cycling past my friends house to go to work. After a few weeks, I started to notice a traffic light which is always green! It was the same light my friend told me about. I remembered.

It is here: https://goo.gl/maps/2cgcx1b92LL2. Streetview direct link: https://www.google.com/maps/place/52%C2%B000'00.9%22N+5%C2%B...

Seems to be for pedestrian crossing. Isn't there a push button on the pole?

I guess it's like the "no smoking" lights in airplanes. Even though they're always on (it's not like there's times during the flight when you can smoke and other times when you can't), they serve as an important reminder, and therefore have a purpose.

> I guess it's like the "no smoking" lights in airplanes

On newer planes the no smoking light is now only a sticker/sign. They're using the bulb that used to be for smoking now to indicate when WiFi/GSM is available (satellite based, so only above 20,000ft).

At least this is my experience flying internationally from Europe in the past years.

> satellite based, so only above 20,000ft

Wha?

I'm guessing it has to do with the frequencies/power levels they're using for communications not being permitted below 20,000ft, although I haven't dug much into it.

The brochure on my flight said the plane had a 5/1MBit link (shared between all users). Not exactly what you'll watch YouTube videos on, but I suppose it works for email and message apps.

https://www.panasonic.aero/inflight-connectivity/global-comm...

Of course, the lights used to go on and off when smoking on planes was permitted.

I'm not 100% certain, but I'm willing to bet it's still permitted in some countries.

I don't know anywhere it is officially permitted for passengers, but anecdotally it still happens in some countries.

http://liveandletsfly.boardingarea.com/2016/07/27/smoking-on...

In practice Air India seems to allow it, especially on the older jets and longer flights. Unusally long lines immediately form at toilets and don't seem to subside throughout a several hour flight. The smell of cigarette smoke is attended to regularly with a good old spray of air freshener.

What???? I doubt this is true. Smoking has never been allowed in numerous Air India flights I have taken.

Agreed. I've taken various internal flights in India, Vietnam and the Philippines and none of them have allowed smoking, officially or "unofficially".

No, the other arms of the intersection are actively using lights so by regulation this arm must also be light regulated. They can't remove it even if they wanted to.

They are there because of the regulations. You'll also find an ashtray in the bathroom. It is because the regulations have not changed since the times that people were allowed to smoke on planes.

With respect to the ashtrays in bathrooms, I've also read [1] (no idea if it's true or not) that the FAA still requires them on the theory that, if someone illegally has a smoke in the bathroom, they want there to be somewhere safe to stub out their cigarette.

[1] http://www.telegraph.co.uk/travel/travel-truths/why-do-plane...

This sounds like it could be straight out of The Hitchhiker's Guide to the Galaxy.

Fucking Vogons

Or Catch-22

Or Yes, Minister

I get why that road is signalled. It intersects right in the middle of another signalled intersection.

But in my neck of the woods we'd probably show a green right arrow when intersecting traffic from the left is stopped at a red light.

Ah, thanks for pointing that out. The green arrow is definitely what we'd have here in the US.

The green arrow is pretty common in former-Soviet areas (Dresden is near the Czech border). Usually it's used at crossroads, so if the crossing lane is clear or not busy you can still turn right without being held up. Here is a good example near me:

https://www.google.lt/maps/@54.7056651,25.3040075,3a,75y,99.... (And if you go forward two steps the Google car goes through the red light :D)

If you aren't used to it you need to be careful though, as often the street you are turning into is green for pedestrians to cross - so you need to give way. Usually you can use this lane if you are going straight, so it's somewhat courteous to go over one lane and not to block it.

At least in Norway the green arrow doesn't only tell you that you are allowed to make the turn, but it also tells you that other traffic has red light so that you know you are guaranteed the right of way.

In some places (definitely in Norway) a green arrow doesn' just imply you can turn right if safe; it tells you other traffic is halted and you've got the intersection all to yourself.

Edit: ninja'd by runholm

That's the situation in Germany as well.

In the UK a solid green light means proceed if safe to do so but you may not have right of way and there may be intersecting traffic.

But a Green arrow means you can proceed in the direction of the arrow and you have right of way with no other intersecting traffic.

There was apparently a rule change in recent years, as I've seen a non-protected turn is now indicated by a flashing yellow arrow.

Yep, in Australia there would be a painted arrow on the road, a 'Left turn permitted on red after stopping' sign, and the opposing traffic would be stopped every few minutes for this one to go green for a few seconds just in case (so as to not confuse people, and in case in a really busy time the traffic on the opposing way was too busy to let enough people through to stop the left turn way backing up).

Is it in the red light district?

(When I was a child, I actually thought that the meaning of that phrase was related to traffic lights. I was so naïve.)

You probably thought that Roxanne was a traffic engineer.

Sting was the pointy haired boss meddling and micromanaging in her project.

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.

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.

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...

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...

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.

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

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.

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.

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

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...

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".

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.

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)

Ok, why not just put up signs saying "do not enter" and "right turn only"? And, then, just have a signal for the assumed protected right-turn (Germans do drive on the right, correct?)

This "solution" seems very confusing. In every US/Canadian jurisdiction I've visited has nothing like this German solution. Just indicate with lights, signage and road furniture that the particular route is not allowed. To technically keep the route open, but prohibit by lights seems prone to confusion, especially for individuals not from the area. Also, how do mapping apps deal with this intersection (curious)? Do mapping apps properly route through such an intersection?

(edit: clarity)

Take a look at the light: https://news.ycombinator.com/item?id=13873787

Any jurisdiction in North America would just put a Stop or Yield sign there.

In North America, they use a stop sign for basically every situation. So the continent is plastered with stop signs, none of which show their intent.

I'm not sure what you mean by this. The intent of a stop sign is to require the driver to stop and check that it is safe to continue before doing so. I don't see how a stop sign could fail to convey that intent.

In the rest of the world its a given that you'll check its safe to continue before driving through an intersection ;)

Around here (Norway), stop signs are only used at particularly risky intersections.

To illustrate how rare they are, I can only think of two within a 100-mile radius[0] - both in places where you are about to enter a road with a 50mph/80kmh speed limit and where visibility is terrible in either direction.

[0] In fairness I should mention that 2/3 of that circle falls in the Norwegian Sea, where stop signs are exceedingly rare...

> Around here (Norway), stop signs are only used at particularly risky intersections.

The same as in Bucharest, Romania. That's why when I see a stop sign I make double-sure when looking for cars who have right of way over me.

He must be talking about the four way stop crossing, a thing that is entirely unheard of in Europe. Over here, if no road gets priority, it's either a roundabout or priority to the right. In case of a deadlock, all three solution become first in first out, but only the four way stop requires everybody to shed all inertia even when the resource is not contested.

Compared to the countries of Europe where I have driven, the American traffic I have experienced often seemed excessively polite, to the point where I think that (relative to Europe) it would be more socially acceptable to drive bad because of being dangerously distracted than to drive bad due to being in a hurry.

I have long suspected a causal relation between the politeness and the four way stop, I just can't figure out the direction of causation.

Obviously roundabouts are fine. But an unsignaled intersection? Most intersections do not have nearly enough visibility to make a go vs. yield decision while you're going at full speed and traffic from the left or right is also going at full speed.

Easy one: you don't approach such an intersection at full speed. The difference between safe speed and a complete stop is substantial (even more so if you can pretty much ignore one of two directions).

> Easy one: you don't approach such an intersection at full speed. The difference between safe speed and a complete stop is substantial

I still have to slow down a lot because I'm not sure how fast the other drivers are going. At that point it's not a big deal if I stop.

> even more so if you can pretty much ignore one of two directions

That sounds like an intersection that would not be a four way stop in the first place.

Why would everyone blow through an intersection at full speed?

Sometimes stop signs are used because of interference with other drivers (check it's safe to checking other drivers), sometimes they refer to pedestrians (check it's safe by checking pedestrians), sometimes they refer to some other kind of danger, for example it could be something like speed bumps. Basically a stop sign is there to tell you to stop (even if it's not really necessary) and watch out for something (without telling you what).

There exist all sorts of signs that actually tell the driver what to watch out for, and make the right of way situation clearer. But in North America, a stop sign is used in most situations.

Four-way stop signs are another form of silliness. They often happen in residential areas where small streets cross. In Europe you'd have 'right before left' rules that only really matter when cars actually meet; in North America you have to come to a complete halt, constantly.

I'm no driver, and am not a big fan of drivers or driving in general. But I kind of understand why drivers are so aggravated here.

You stop and then wait your turn to proceed. This is the same meaning everywhere in the US and if there are additional restrictions there will be separate signs imposing them.

What is it that confuses you about them?

From what I understand, the difference is:

- In Europe a stop sign means that you have to wait until the way is clear. Of course, you normally don't have stops on more than two of the roads crossing. (Theoretically, you can wait forever at a stop, since people on the other roads won't stop and let you through)

- In North America (I've seen it in Canada), you have stop signs on all four roads crossing and you get through in a first in first out turn.

It seems to me that

- the US uses stop signs as a way to slow down the traffic (so, no real meaning), but

- in Europe it does have a clear meaning: "it's dangerous to drive over a crossing without halting". Not only you have to be careful because you have no right of way (the "give way" sign) but you really have to stop and look at the traffic, mostly due to poor visibility (or high difference in speed).

There's two types of stop signs in the US- normal stop sign and a 4 way stop. 4 way stops are marked as such. Normal stop signs work "like Europe."

In practice stop signs don't work at all in the US. People roll through them, sometimes not even slowing down and can't understand whoo goes first at 4 way stop. So they either sit at the stop sign frantically waving on all cars that are approaching until no more cars are approaching or they just go at some random time or they just blow through the sign altogether.

Anyways, 4 way stops aren't just for slowing down traffic, though they are sometimes used that way. They are for when you have two roads coming together that both have roughly the same amount of traffic (no 'main' road) but don't want to put in a light.

The set up described in the article is actually equivalent to "come to full stop, then right turn only".

You cannot replace the light with a sign because by law traffic lights have higher precedence that traffic signs. This is for failover reasons (when traffic light is broken, no electricity etc.) So a sign on an intersection can be rendered void/meaningless if the traffic light is operational.

Having traffic lights show the same light is not that unheard of as the article makes it sound. I visited a part of Europe where right turns on intersections always showed blinking yellow light. This is equivalent to "turn right, but yield first"

I understand it can be confusing if you are coming from the US system though. The European system is highly standardized for use in all kinds of driving situations (like places with unreliable electricity), the drawback is that it can get a bit technical at times.

> So a sign on an intersection can be rendered void/meaningless if the traffic light is operational.

But that's a moot point if the light isn't there in the first place.

I'm sorry, but no matter how you slice it, this light is stupid. What is needed is simply a pair of signs: STOP and RIGHT TURN ONLY.

It is mandatory for there to be a light at the intersection by law

Yes, I get that. But it's a stupid law, and it should be changed. Traffic laws are not handed down by the gods.

Yes great idea. Build a new rule into a nation-wide law just to solve a problem that needs no solving as "red light with static green right arrow" is a typical sight over here in Germany and drivers DO understand it.

It would be much better to change traffic la nation-wide so we can get rid of this ONE traffic light in Germany. Isn't it?

Yes, that light is costing tax payers every year to operate it. The law should be changed so that there is no need to do this.

How much do you think it will cost to verify that such a legal change will not have unintended side effects?

Changing the law and checking correct enforcement costs way more in people hours than the cost of operating a single traffic light. People underestimate the cost of regulation. Also, a consistent and simple set of rules should always be preferred and causes less human errors.

Changing the law costs a lot, lot more you know..

Yes. It's stupid for a law to vest absolutely no discretion in the engineers so they may adapt to peculiar local situations.

This light is an at intersection, the other three roads leading to the intersection have traffic lights too.

If there is a power cut, then the other three roads will have no lights, drivers there will treat the intersection with one set of rules. Whereas the driver on this road with a sign will treat the intersection with another, potentially causing an accident.

There is no more possibility of an accident with a stop sign than with an always-red light because the rules for both are exactly the same: stop, and proceed only when there is no conflicting traffic.

"But that's a moot point if the light isn't there in the first place."

When I said "traffic light" I meant the entire set of traffic lights of the intersection. You can't have just one lane without traffic light and all the others with. It would be highly confusing, also probably against the road laws.

The point of the traffic light taking precedence over road sign is actually part of the rules of the road. It is also required knowledge for driver exams.

> You can't have just one lane without traffic light and all the others with.

Of course you can.

> It would be highly confusing

Why?

> also probably against the road laws.

Laws can be changed. The fact that "it's the law" is a stupid reason to keep doing something that doesn't otherwise make sense. Germans of all people should understand this. (And BTW, I am German.)

There is a sign in Germany that indicated "must turn right".

https://en.wikipedia.org/wiki/Road_signs_in_Germany#/media/F...

Combine that with a stop sign to force a stop and yield.

It feels like this would solve the situation without the need for traffic lights. I'm sure I'm missing something though.

From what I have gathered, the reason is that all sides of a junction must have traffic lights or none. Because traffic lights are needed at the other entrances, this one is installed to comply.

Because (as I understand the article) their laws don't allow for intersections with a mixture of traffic lights and static signs.

It's a great illustration of a point that came up a while ago in that discussion of 'what makes a good programmer vs. a great one'. A good programmer recognizes the value of consistency, and leaves the red light in there even though it's a bit ugly and inefficient, because that keeps the system consistent. A great programmer would change the rules to allow a more efficient solution which solves the real problem (ie. cars need to know what to do.)

In that case a 10x-engineer would do a quick calculation and notice that adding and enforcing yet another exception to the law is much more expensive than operating a single traffic light. Note that laws are enforced by humans rather than idling CPUs, so every single rule adds real workload.

That's an incredibly German perspective. Somehow in other parts of the world, practicality is allowed to take precedence over rigid adherence to authority, and it seems to work out fine.

Reminds me of catching hell from random old German ladies in Berlin when I crossed a sleepy residential street, without a car on the road in sight for miles, without waiting for the crosswalk light to go green. Or gasp crossing a street without using a crosswalk!

Or would realise that changing the wording slightly (not adding an exception, just updating the wording of one clause) to allow using a sign in place of a non-changing light would be a small enough change to get instantly rubber-stamped (so low administrative implementation cost), and would be trivial to enact because we already know that there's only one place where it applies.

This traffic light in Harrison, NY has been green for decades: https://www.google.com/maps/@41.0142226,-73.7217408,3a,75y,1... I have been driving through there since the late 70's and I'm pretty sure that the intersection configuration was in place earlier than that. So it's likely that this light has been green for over fifty years.

I've been through there before and it makes sense. They want the whole exchange signalized for consistency but that one lane's configuration means it's protected.

I imagine you can make it red at the control box for an emergency or construction; I wonder if that's ever happened.

How did it stay red during bulb replacement? Article is totally misleading!

I find your lack of faith disturbing.

Also the article implies it's just on a very long 28 year cycle, but then it says it never turns green. Which one is it?

When you have a steady, well working system and only one special case that causes that system to waste resources, you don't put special if cases and switches to optimize for this special case. Especially if it's one in a million.

I object for having to pay for the green and yellow light bulbs. They should be empty on purpose.

Then the crew changing the lights would need a second checklist. The chance that they apply that wrong one to a regular intersection is not negligible.

If they're empty to begin with, new ones shouldn't be put in. How hard is that?

It's harder than it looks. I see two possible interpretations of your proposal:

a) Not change the worker's checklist. That would mean they should deviate from the list, creating a dangerous precedent.

b) Adding another rule to the worker's checklist. Great, now they need to check this for every single light they are working on, which means more work (is that really cheaper than the bulbs even if it's only a few seconds per light?) and more possibilities of doing mistakes.

Not to mention that the traffic light probably refuses to turn on when not all lights are installed. That means the software needs to be changed. Yet another possibility to introduce fatal mistakes at other intersections.

I prefer paying for a bulb every now and then to putting human lives at risk. Note that changing something for this intersection means changing things for all intersections, including high-traffic complex ones.

If a variable is a null, you can assume that it should be null - but what if it became null as an error? We can put in a special code to check that, of course, and put in more branching in already complicated codebase.

Or we could admit that these two objects wasting space are quite an acceptable price to pay, relative to the scale of the system and of the price of adding additional logic to it, which always equals instability and defects.

Does it really cost ~500€ per month to run a single traffic light?

How many drivers a month avoid losses thanks to this traffic light? I'm gonna guess the ROI is positive overall on traffic lights.

*Sent from my iPhone while driving 75 on the freeway, eating fast food listening to a book on tape, navigating with Google Maps

(Not really, but people do this)

I was surprised too - the article seems to address 'why on Earth has this light been red for decades' but open and leave the bigger question of 'why on Earth does powering a single light cost €5500pa'.

There are two lit lights on the pole, so you can halve your astonishment :)

That is true, but the figure seems to refer to one:

> And the total cost of maintaining this one traffic light over almost three decades runs to roughly €150,000. Every year maintenance and running costs come to €5,500.

'Traffic light' is used throughout to refer to the one that's been red for 28 years; not the whole system.

Regardless, I don't think I'd have been less surprised or inclined to comment on it had the article stated the cost was €2,750pa!

I'm hopeful that this cost figure is a result of a journalist getting details almost right as they so often do.

In my local town, I've heard a figure of $100,000 to install a new light. If we assume similar costs in this case that's $3,300 per year right there and we still haven't powered it on or put any money into monitoring it nor maintaining it. The systems in place for monitoring are largely a fixed cost across all of the traffic lights in the city. I can only guess that maintenance costs are lower with newer lights and increase with age.

If the number quoted in the article includes the initial outlay to erect the signal, then I don't see the 30 year cost being that out of line. If that cost is truly only maintenance and operation, then it does seem quite excessive.

> 'why on Earth does powering a single light cost €5500pa'

Exactly. I can sorta understand the argument that if the intersection has lights then this street needs one too even if it's always red, but for me the real WTF was

if one red light costs €5,500 yearly, how much are we (over)paying for the whole system?

Exactly why I have a resistance to government 'solutions' when it comes to anything beyond constitutional basics. Governentnt is rarely more efficient than the free market/private sector. Those jackasses actually have the green and amber light bulbs included in the maintenance.. those bulbs got replaced as well. €5500 yearly -- even if a guy got paid €100 per hour, how could a a single light require that much expense? Is someone inspecting and maintaining it on a daily basis? Concierge traffic light service?

Assuming 100W light bulb and 0.3€/kWh cost, it's ~22€ for the electricity. So I guess we're left with the maintenance. These guys have pretty decent hourly rate even if light bulbs need to be changed every few months ;) But in all seriousness it seems somewhat understandable. During all these years you may need to change the pole, some elements, maybe repaint the pole, maintain cars and equipment of these guys who change the bulbs and so on. Plus it seems likely that it was calculated as city traffic light infrastructure expenses divided by the number of traffic lights. Then you have some upgrades of electronics, leds, counters or cameras in other parts of the city.

I'm not trying to say that governments spend money efficiently, just that the figure may be not as ridiculous as it seems.

Don't forget the people employed who keep watch over the whole lights system. It's not fully automated afaik.

Yes, and in this case it's just the amount of man hours spent monitoring the system divided by the number of lights because in this case there's not many decisions to be made by the monitors.

Another thing re maintenance: When I saw a TV segment about these lights, they mentioned that the maintenance crew will always exchange all three lights, despite yellow and green never getting used. The reasoning is again consistency: If you told the crew to specifically not replace these two bulbs, there might be a mixup and they would end up not replacing some vital bulbs.

Who still uses bulbs for traffic lights these days? Here it's all LED. Cheaper and much clearer. (The old bulb lights were sometimes really hard to see when the sun is low behind you.)

Lost of places. Here it's a mixture of lightbulb and LED lights. Also LEDs may be cheaper over time due to electricity costs, but the initial upgrade is surely more expensive than a new bulb. Then there is the problem with snow not melting and you don't know what maintenance contracts are there for bulb replacement and how long those last.

We are talking about the average cost over 30 years. There were no LEDs used in traffic lights for the better part of that time, and I have no idea about efficiency of light bulbs in the 80s.

I had a German colleague come to visit me in the US one time. When we went out to lunch, and I made a "right on red after stop", he just about put his foot through the floorboard trying to push his invisible brake pedal. German driver training is very thorough. :)

I'm not quite understanding the reasoning behind this. It seems a stop sign plus a "right turn only" sign would imply the same rule.

Because the regulations state they can't have an intersection controlled by both signs and lights. The rest of the intersection is controlled by lights.

I'd just like to understand how on earth it costs 458€ per month to maintain this single light?

Does anyone have some insight into that data point?

Edit: I know the 150k over 28 years number is a bit rounded, but even using that it's 446/month or 14.60/day to run the light?!?

Googling, I've seen the rough figures from $1,000 to $10,000 (USD) a year to maintain a traffic signal -- all over the place for sure, but the €5300/yr cost doesn't appear to be that out of line. However I can't Google a really good breakdown of costs.

My assumption is that the bigger percentage of that is maintenance. There are three lights in the Google street view. Assuming these are old incandescent bulbs and Germany's high kWh price, electricity costs would be roughly be about €1500 at most a year (assuming €0.35 per kWh, 150 watt bulbs, and 3 lights "always on"). Maybe add another €500 at most for the controller although it probably should cost less than that. (LED lights would drop this part of the bill a lot, too.)

However, there is probably some maintenance costs for both the controller and the light: changing all bulbs yearly (if incandescent), cleaning the bulb lenses, controller maintenance (wiring checks, etc.), etc. I imagine that the bulk of the costs would fall here: labor costs plus some equipment costs (trucks, tools, etc.).

A) http://pugetsoundblogs.com/roadwarrior/2012/09/25/comparing-... B) http://bmtsonline.com/sites/default/files/Reports%20and%20Do...

Even if 2000/year is the base electricity cost, that still means it's costing 9.20/day in materials and labor for a single light. That still seems very excessive to me.

Let's assume a North-South/East-West intersection. Eastbound traffic (on the Western road) sees this light.

If the Eastbound traffic can only go right, I presume the Westbound traffic can only go left. (Otherwise the Eastbound traffic would be permitted to go straight and/or left.) If that is true, then the Southbound traffic can only go straight; no turns. (It follows that there is no Northbound traffic.)

In essence, three roads converge to one. If that's so, why is this an intersection? Why not merge the roads or build a wall making incorrect crossings or turns obvious?

Do they use steady red lights for all "right turn onlys" which on the other end have opposing traffic (do not enter)? Or is this an exception to the right turn only + do not enter at the other end? Harrison and 10th[1] in SF for example.

[1]https://www.google.com/maps/@37.7714317,-122.4115453,3a,75y,...

This is an exception and a too-clever-for-its-own-good use of a traffic light. Usually we use a blue sign with a white arrow pointing right to show you can only turn right.

Thanks for the clarification. It's a bit odd in that it already has the right turn only sign but they decided to also install a traffic light --maybe the solid striped median line and the right turn only were not enough to signal people and there were enough accidents that the DoT decided to make it really obvious that vehicles should not cross.

It does not have a right turn only sign. It just has a green arrow.

The only reason you can only ever turn right is because the light stays red, if it were to turn green you'd be allowed to cross the intersection in any direction.

There are also different rules that need to be followed when crossing the intersection on account of a green arrow than, if it were merely a turn right only situation.

Half meter above that green arrow right, is a blue right turn only sign. It's on the same pole.

The traffic light takes precedence over the static sign (which is only there as a fallback).

Germany does not usually have "right turn only"s, at all. That’s the simple answer – this traffic light is the only "right turn only" on a normal intersection in Germany. (which is why it has its own wikipedia entry, and website).

It does. "Right turns only" is a white bent arrow on a blue ground. But it does not affect precedence like a red light with a green arrow does (or a stop sign would for that matter). You often see it on T-junctions with one-way roads.

Yes, and no. That’s a right turn only at an uncontrolled intersection. Germany has none at controlled intersections (those with traffic lights).

I could swear I've seen "right turn only" signs at controlled intersections when coming off the Autobahn. I think it was for a right turn onto a B road.

I wonder if this article (from 2015) has now become obsolete? I notice that the OSM of that location[0] appears to indicate that Ziegelstraße now dead-ends just before the relevant intersection, and the Bing satellite maps, though difficult to interpret with all the tree cover, appear to match that.

[0] http://www.openstreetmap.org/#map=18/51.05376/13.75783

Yes, the road is now a dead end.

Why does the signal include an amber and green light?

Probably because including two unused bulbs is cheaper than custom-making a single-bulb traffic light.

(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.)

Actually, it’s not that easy.

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)

That doesn't sound entirely true.

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.

Actually, I’ve got a few intersections right near me with such examples.

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).

Where in Germany are you?

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.

In California, I've seen single-socket traffic lights in all three colors. So it wouldn't have to be custom-made. The green ones usually have a directional arrow forward (amber and red usually blink) so they could probably accomplish the same effect with stock parts: red arrow pointing right in a single socket.

Just don't put in new bulbs, then

Probably because it's a traffic light. If it's a traffic light, it'll have to conform to specifications for a fully operational traffic light.

Woe unto the traffic-light maintainer if, should the powers that be change the light timing, the light doesn't function correctly.

A color-blind person wouldn't know if a single light is red or green.

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.

This is correct, but I'm not sure the authorities take that into consideration. In my case, it's the yellow and red that look identical, but that doesn't stop them from making single flashing red lights and single flashing yellow lights. Makes life exciting sometimes.

I don't think I've ever seen a single flashing red light that wasn't accompanied by a stop sign.

I've seen several in the american south east. Usually around schools or churches (where they'll flash red when church is letting out)

It's not just color blind folks. San Jose's street lights are, to my eyes, damn near the same color as yellow traffic signals. I have to look for lights moving in the same plane as the road unless they're red or green.

What's the difference between flashing yellow and flashing red?

Flashing yellow simply means caution. It is meant to draw your attention, but it has no specific legal meaning beyond that. Flashing red is equivalent to a stop sign: i.e. you must come to a complete stop, but then you may proceed if and when it is safe to do so.

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 the UK, flashing amber means "yield to pedestrians at this pedestrian crossing", FWIW.

Cool. I travel enough that this is actually worth knowing.

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.

I suspect I was unclear. A permanent flashing yellow light on top of a pole (not a traffic light) will appear next to a zebra crossing, and it indicates "this is a zebra crossing; pedestrians have priority over traffic". A flashing amber light as part of a traffic light may appear if there is a pedestrian crossing also controlled by lights, and the flashing amber light means "the pedestrians are about to be shown a red light; yield to pedestrians if they are present, but you as a driver are about to receive priority and may in any case proceed if there are no pedestrians".

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.

I guess I may have also been unclear. Pedestrian crossings at traffic lights are controlled by the lights. Otherwise, pedestrians officially have priority.

In France, flashing red means an absolute stop, it's like a solid red light but for more dangerous situations. Most often for unguarded tramway level crossing. It's not very common though.

Flashing orange means yield (including to pedestrians, though few people are aware of that).

According to the article -- which I assumed others had read before commenting -- the other lamps have bulbs in them.

My assumption is that the different coloured bulbs are ordered from the manufacturer in equal quantities.

Looks like not many read the last para:

> 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.

Maybe they change all three bulbs at the same time for uniformity — I don't think I've ever seen a traffic light where one color is burnt out.

"It's not a bug, it's a feature"

Surely, a stop sign: https://www.stickergenius.com/wp-content/uploads/2013/02/sto...

Plus a "turn right only": http://l7.alamy.com/zooms/95a9489a7d8b4c418cb6cfd3b6753295/r...

Would achieve the same effect? People would have to stop at the intersection, and then they can only turn right. Same as red light+green right arrow.

edit: sorry, yes, I now understand - it has to be a traffic light because all other sides have traffic lights.

Presumably you could modify the way the road intersects to make it an inlet (which automatically has lower precedence regardless of lights) but that'd probably just be as confusing.

There is a denial-of-service attack possible.

Red light with green arrow means you may turn right if you feel like it or wait for green. Just park your car in front of the traffic light... it'll be fine.

Parking is not allowed on direction lanes (this one is a turn-right lane). You may halt your car there, but you may not leave it (thus park it). So while you can do this, you will also block yourself from doing much else.

Of course, a DDoS attack would be possible by having a couple of friends and switching the driver every once in a while.

A witty state lawyer may also try to sue you based on StVO §30 (1), though winning that trial won't be very likely, because you can simply stop the engine (allowed at traffic lights).

They could still get you for plain old obstruction. The thing about laws that makes them different from code is that intent matters. Even if you follow the letter of the law you can still get into trouble if you blatantly obviously try to violate its spirit.

I don't know the intersection but StVO §12 probably applies as it's likely to be within 5m of the intersection (3/1.) and thus parking isn't allowed.

Would that light actually stop anyone? In France and Italy, traffic lights are just recommendations. We once got honked at for waiting at a red light when there was no cross traffic.

Given Germans' penchant for carefully obeying even pedestrian crossing lights, I suspect traffic lights are a rule, not a recommendation.

Yes. In Austria, you run a red light twice, you can lose your driver's license. Cross a red light as a pedestrian and a heavy fine is awaiting you.

Not true.

Crossing a red light is a pretty strong traffic violation in Germany. If the light was red for longer then 1 second apparently 200€, a 1 month driving suspension, and 2 out of 8 points to lose your license.

https://www.bussgeldkatalog.org/rote-ampel/

So for running a 28 years long red light would be decapitation and two consecutive perpetual prisons.

Luckily Germany abides by the international convention on human rights and doesn't have the death penalty so it'd probably be three life sentences. And because of § 54 section 1 StGB they'd be flattened into a single life sentence, which in practice translates to "at least 15 years".

The German equivalent of "life with no chance of parole" would be "Sicherheitsverwahrung" (preventive detention, consecutive to the life sentence) which is an extremely dodgy instrument that is probably in violation of the constitution and the international human rights charter if you look too closely but still used when punishing people who probably should instead be treated for difficult mental health problems.

But I admit that makes for a less funny joke.

Yes, we Germans generally stop at red lights (even a lot of pedestrians do so). I guess most of us respect most of our traffic laws (except for speed limits).

I think the only speed limit generally not observed is 60 km/h in construction sites on the motorway, which seems to be interpreted by pretty much everyone as »Continue driving 80 km/h«. Otherwise, at least around here, it's just a few drivers that go faster than allowed but the vast majority keeps to the limits.

That's actually not correct. One example from Düsseldorf: http://www.rp-online.de/nrw/staedte/duesseldorf/duesseldorf-... (2/3rds of drivers in a 30km/h zone are breaking the speed limit).

30 km/h and even 50 km/h are respected pretty much nowhere except where there are stationary traffic cameras. I ran across an article recently (can't seem to find it again) where 90% of German drivers voluntarily admitted to not keeping to the speed limit.

For most people, breaking the speed limit does not seem a big deal. Then they run over a kid and say "I didn't mean to do that"! Well, they did in a way - keeping to the speed limit is not hard.

In most Europe (non-South) countries pretty much everyone obeys traffic lights, even if there's no traffic. That's because you could lose your driving license in addition to hefty fine for such violation and because some (most) of the intersections are watched by CCTVs now.

For pedestrians it is true, but for vehicles it is quite an exaggeration (for France). Well, for the red light, because for the yellow light is often understood as "accelerate so you can pass become it becomes red". When I go to more respectful countries (Nordic or Germanic countries, or Japan) I am always (pleasantly) shocked by how respectful drivers are. For example in Austria people literally braked to let me pass at a pedestrian crossing on a large road. In France you can wait for minutes for a car to stop or for the traffic to stop.

> In France and Italy, traffic lights are just recommendations. We once got honked at for waiting at a red light when there was no cross traffic.

I don't know about Italy, but in France red traffic lights are absolutely respected by everyone (almost, obviously there will always be people who run red lights).

You'd lose 4 of your permit's 12 points (6 points if you're a young driver) for running a red light, and depending on the policeman's judgement your license might get suspended for up to three years. It's among the highest class of violation you can make.

If you got honked at a red light, I suspect there was something you didn't notice, like a blinking orange light allowing your lane to pass, or something like that. Or just the driver behind you honking by error while fiddling with something in their car.

Wrong, you should just ignore those people that always seem in an hurry and will honk at anything.

> While this may seem nonsensical and a waste of money to your average motorist, the Dresden authorities can explain in exact detail why the light never changes colour. And their explanation might show another habitat that dies hard - a love of convoluted, self-defeating regulation.

That seems unnecessarily critical. Clear and consistent communication is pretty important when you're talking about traffic, and the cost is surely a drop in the bucket compared to the city's overall budget.

Rt turn on red is voluntary. Not one to have road rage much but I enjoy waiting for the green if a jerk is behind me.

Also being paid by the hour to drive red lights are your friend

This is so german of you!

I am German (and drive a car) and as per my understanding this traffic light could simply be removed with the only change necessary being a stop sign instead of the Yield sign.

The explanation given by the city (or its translation) don't make any sense to me.

EDIT: After re-reading the explanation I guess the idea is that since the crossing street shows a green light, the "opposing" street must have a red one.

Funnily enough, there is precedent, that a red light can be ignored if it doesn't change for 5 minutes. And I really doubt that there isn't a way to regulate the crossing without a permanent red light.

http://www.stvo.de/info/faq/165-ampel-bleibt-rot (German)

That allows you to assume that the traffic light is defective, in which case the traffic signs would apply and require you to turn right—but that is exactly what is allowed by the green arrow even at a red light.

ah you are right, probably there is a blue right-turn only sign (I just thought about the Grünpfeil depicted in the illustration image).

Perhaps they could put a physical barrier in front of that, so that it's no longer possible to go forward, and then it's no longer part of the intersection?

-Then again, would that be cheaper or less confusing than simply keeping the light?

I think it's certainly less confusing to put a physical barrier. I could see myself waiting for the light to turn green :) . And it shouldn't cost more than 10.000 euros (a couple of years of maintenance of the traffic light).

I don't understand which of the lights is the offending one:

https://www.google.com/maps/place/G%C3%BCntzstra%C3%9Fe,+Dre...

First of all, the offending light, if you can call it that, is the one where Ziegelstraße opens into Güntzstraße, here: (0).

Also, the only way that unit maintenance cost makes sense is if it is calculated by taking whatever amount they spend on anything traffic-light related in a year and divides it by the number of traffic lights; that infrastructure remains in place even if this light is removed.

So - you don't really save anything except the annual maintenance trip, whose cost is probably measured in the low hundreds (educated guess: two blokes with high-visibility vests, driving a VW Caddy packed to the gunwales with traffic light bulbs to the site, spending ten minutes swapping out the light bulb before proceeding to the next light.)

Also, you'd need to change the law for it to happen.

That being said, I suspect I'd keep you company waiting at that light; when in doubt, I tend to not move into traffic just to see what happens... :)

(0) https://www.google.com/maps/@51.0539102,13.7575856,3a,75y,11...

I'm curious, do self-driving cars handle a case like this without intervention from the driver?

If they want to drive in Germany, they should surely know the local driving rules (including the green arrow sign), otherwise there'd be little point in a self-driving car. And since there is no way of not going right at this point there should be no problem.

But I don't think there is much self-driving in city traffic yet. Especially rules about who has to yield where are not always governed by signs visible directly to every driver (e.g. Verkehrsberuhigter Bereich).

"And their explanation might show another habitat that dies hard"

Another... habitat?

should put red plastic or colored paper there. or just paint it red.

Looks like some traffic lights from my town.

It's not red when they're replacing the bulbs for maintenance or when there is a power outage. So this story is false. Also this is a pretty random story to be topping HN. Sure there is an edge case where this could happen, so what.

32 points and not a single comment. OK, I will bite.

> But anyone who waits to cross into Gerokstraße could be waiting a long time - almost three decades if they are patient enough.

Did anyone notice the awesome pun ? If you wait that long, you will become a patient :-)

I don't see the pun. Can you explain it?

patient - able to wait long enough

patient - you wait so long that you'll fall ill/die, thus becoming a hospital patient

thats nonsense, and not a pun

Maybe it's that famous german sense of humor...

Clever, but I don't think that was intended. Too subtle.

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