In city streets, the car sometimes fails to correctly detect the speed limit, let alone driving autonomously. Also the Germans apparently love making the rules in every junction different, and while most people are capable of intense street-sign following (I feel like a robot when driving, yeah the irony is not lost on me), I doubt a computer can do that too, especially when every mistake has a bigger chance to end up with an accident, compared to (I imagine) anywhere else in the world, because a typical driver here doesn't want to calculate the risk of another failing to follow the rules correctly.
Look at driving fail videos from Germany and the ones from Russia and the USA, you'll regularly see something they show as "huge mistake OMG" in Germany being unremarkable (if not business as usual) when compared to others.
I've been in a Tesla running the self-driving beta in Manhattan and it is NOT fun or relaxing at all. The car is overly "jumpy", but by jumpy I mean "breaky." The way a lot of pedestrians cross streets (walk into the side of the road and get 2 feet away from a passing car before crossing right behind the car) causes it to slam on the break constantly while people "stage" their crossing. It's also terrible at left turns without a light. Both of these flaws are completely understandable because it's a complex safety situation, but people who think human drivers are replaceable within 5 years are naive.
I always wonder if this is a problem that has to be solved at all. Instead of cars recognizing the speed limits there should be government managed maps containing all the roads/lanes and speed limits.
When creating a construction site just add it to the map.
If you can legally rely on the speed limits in the maps, this should be much easier to do.
Recognizing speed limits seems to be a technical solution to an organizational problem.
In Germany a speed limit doesn't mean it's always reasonable to drive at maximum speed.
E.g. there are narrow streets in citys with cars parking on both sides. The official speed limit is 50 km/h. If you drive at this speed you straight up murder any pedestrian coming out behind of a car. If you do this you'll be pleaded guilty, because your speed was not appropriate to the situation. You even have to learn this exact situation when you make your drivers license.
An other funny example. Where i lived was road with a bend, where an ordinary person should maybe drive 50 km/h. It was borderline questionable to drive through there with 70 km/h and a good car.
Directly before the bend the speedlimit changed from 70 km/h to 100 km/h. There where a lot of accidents, because even germans don't understand the meaning of german speed limits.
I’ve noticed this on Polish vs Czech roads (I’ve driven mostly in the mountains border regions of Czechia so this maybe local). Polish roads have gazillion of signs and usually you’ll see a lower speed limit sign just before the curve or a bend if it’s not supposed to be driven at the speed limit of the main road. In my opinion there are way too many signs and I feel—as another poster commented here—like a robot. On the other hand in Czechia on a small mountain road there’s a general limit say 90kmh or 70kmh and there’s no way you make the bends with that speed— it’s your responsibility to slow down.
I’ve seen a similar differences in another border regions, e.g. Switzerland-France or France-Germany. It almost seems like there are two schools of thoughts that different countries subscribe to.
I Drive much and Usually I and others get curves etc more intuitively. One has to be a really bad driver to not have a Instinkt for the speed necessary in curves.
Btw German driver here and I find German has a good equilibrium of signs . I have to drive to Paris and Milano for work . Those places are pure mayhem of signs and confusion. I can’t imagine a self driving car mastering some of those places.
Prague, on the other hand, is oversaturated with signs. I guess someone makes money on them, because some are clearly superfluous (Segway bans in distant neighbourhoods where no one ever drove a Segway; Segways were only a bane of the touristy center).
The reason why Polish roads have so many signs is because producing and installing them is an opportunity to make money :) And usually that opportunity goes to a company owned by a relative of some local politician ;)
> In Germany a speed limit doesn't mean it's always reasonable to drive at maximum speed.
I didn't want to imply this. I was just talking about the task of finding the speed limit. Getting from there to a reasonable speed to drive at is a different issue and much more complicated, yes ;)
"Das Ende einer streckenbezogenen Geschwindigkeitsbeschränkung oder eines Überholverbots ist nicht gekennzeichnet, wenn das Verbot nur für eine kurze Strecke gilt und auf einem Zusatzzeichen die Länge des Verbots angegeben ist. Es ist auch nicht gekennzeichnet, wenn das Verbotszeichen zusammen mit einem Gefahrzeichen angebracht ist und sich aus der Örtlichkeit zweifelsfrei ergibt, von wo an die angezeigte Gefahr nicht mehr besteht. Sonst ist es gekennzeichnet durch die Zeichen 278 bis 282."
The translation of this is: If a speed limit is combined with another sign indicating a reason for the speed limit (e.g. construction work, dangerous curve, train crossing...) the speed limit automatically ends without any additional sign.
So basically the AI has to understand why the speed limit is there and decide when it has passed the dangerous part of the road.
When starting to drive the car has to recognize if it is inside the city (50km/h or 30km/h limit depending on location), outside the city (100 km/h) or on the autobahn (no limit). This is simply impossible without having a map. You could save the state from the previous drive. But what happens if the car gets towed from the autobahn into a city. Will drive through the city without any speed limit?
That sounds like an exception that could be easily addressed by adding an additional sign or perhaps in most cases making the rule hold for a maximum of 100 yards or so. Even detecting construction work is relatively easy: you have lots of cranes, people wearing helmets, cement mixers, scaffolding, traffic cones, yellow tape, etc. Easy to teach to a machine learning system.
Very true, it's kind of like when you try to automate existing human processes. There are often too many exceptions to make it easy enough to automate, compared to a company that automated this process from the beginning.
Humans are very good at exception handling, albeit slow, and this is implicit in any process involving humans.
Actually, the speed limits are not imposed randomly and you can usually "sense" the limit from the surroundings and the structure of the road. I don't really look at speed limits when driving, if I'm on a road that looks like a pedestrian can walk then I probably need to go slow and if there's a school ahead or the street is particularly narrow or the road pavement is not asphalt I probably need to go extremely slow.
TBF, now I'm not in Germany but when I was, driving on the autobahn usually involved religiously following the signs of speed limit and no speed limit(the limit-free coverage on the autobahn is patchy).
I wonder if the self driving systems asses the road type to determine the speed they should go. Is there a possibility for a autonomous car to speed up to 120kph around a school or in a residential area if the sign is missing or someone puts a bogus sign?
> Actually, the speed limits are not imposed randomly and you can usually "sense" the limit from the surroundings and the structure of the road.
This is, in fact, the legal standard in California! The actual speed limit is the minimum of (posted speed limit plus a substantial fudge factor) and (a subjectively safe speed for the road conditions). i.e. if the sign says 65mph, and the road is winding and a bit icy/rainy so that 45mph is the highest safe speed, you can be ticketed for speeding if you drive 60mph.
It's enforced by the courts generally with fines. You can lose your license with repeated infractions.
The legal standard, like many legal standards, is around reasonableness. Regardless of the posted limit, you may never driver faster than is safe for the current conditions.
And it is indeed borne on the judgement of the officer. Who else would ticket you?
I know it’s not the correct way to do, and it stems from my experience driving, but I’ve always used the first digit in the speed limit signs for bends/corners on mountain roads as a guide for the gear to be in. 25mph curve? Whatever speed you can do in second is fine. 45mph, fourth gear speeds, etc.
Not entirely related but yeah, depends on road conditions and signage.
when there's a construction and the speed limit is 60kph, I really hate it when the car starts accelerating like it's in a race track the moment it sees the limit removed. it scared me a couple of times, so I imagine it's not impossible for that to happen.
it also takes the curvature of the road into account and slows for the traffic, but there's always a small empty town with straight roads...
it also sometimes messes up the steering when going through a construction site with yellow lines, so I really hope that they improved this system heavily in the last year since I bought my car.
Signs are also frequently wrong, even in Germany. This can get so bad that there are multiple maximum speeds on the same road in the same direction, all depending on where you came from.
No, the speed limit is always the same, regardless where you came from. If there is no speed limit posted after a junction, the default speed limit for this kind of road (unlimited, 100km/h, 50km/h, or zone specific as posted before entering the zone, usually 30km/h) applies.
But even a lot of Germans don't know this, I'm afraid.
While this is true it's also not uncommon for signage to be faulty, i.e. not following official regulations, or invalid unfortunately. Most often at construction sites.
Look at driving fail videos from Germany and the ones from Russia and the USA, you'll regularly see something they show as "huge mistake OMG" in Germany being unremarkable (if not business as usual) when compared to others.