back to article Stop lights, sunsets, junctions are tough work for Google's robo-cars

After cruising two million miles of public roads, Google's self-driving cars still find traffic lights, four-way junctions and other aspects of everyday life hard work. To be sure, the hardware and software at the heart of the autonomous vehicles is impressive. But it's just not quite good enough yet to be truly let loose on …

  1. Yesnomaybe

    Just very impressive.

    I think it is incredible that we are even seriously considering self-driving cars. Blows my mind that several companies are seriously pursuing it. What an incredible project to take on! I don't know how soon we will have a mainstream uptake of this technology, but even if it fizzles out, I believe the spin-off technological advance will probably make it worthwhile. I also believe that there is a bottle-neck we have to get through: Once the self-driving cars reach a certain tipping-point in number of vehicles on the road, then perhaps changing the infrastructure a bit to help will become more acceptable.

  2. Anonymous Coward
    Anonymous Coward

    Re: Just very impressive.

    What impresses me most is that these "problem" situations are ones that I have experienced and sometimes failed. I know that I have missed traffic lights when nearly blinded by bright lights and come across road unfamiliar junctions where I had no clue who had priority. The red balloon in the picture would probably have fooled me for a second too in the right lighting conditions. My eyesight is ok (recently checked) so I suspect I'm not alone in making mistakes. In fact I have seen plenty of others drivers do just these sorts of thing. Personally I've not had an accident for 25+ years, and mostly when I see other drivers make these mistakes like me they get away with it, sometimes by luck and sometimes because another alert driver compensates. And this is probably where self driving cars will help the most: they are always alert so as long as they aren't blinded by the conditions they will save us distracted meat bag drivers from our own mistakes.

  3. Anonymous Coward
    Anonymous Coward

    Re: Just very impressive.

    There is no 'spinoff' technology.

    You already have autonomous driving vehicles in terms of ag vehicles which route themselves based on GPS w a known ground station. LIDAR already exists and the LIDAR is being down graded to get the costs in line. GPS? While there are newer sats going up, and you could use other existing tech, like using a known positioned base station, you need a more accurate clock and better antenna. They already exist so no real net new tech. Just upgrades/downgrades on existing tech.

    Code? Maybe, better at decision making.

    (e.g. The balloon in front of the light. LIDAR would be able to identify it as a separate object, however you'd need some more advanced computing power to do that identification so you need to combine LIDAR w photo imaging. )

    Sorry to be a debbie downer, but not really impressive outside of morphing and using existing tech.

  4. Yesnomaybe

    Re: Just very impressive.

    Well the thing about spinoff technology is that it can be of an unexpected nature. If you knew what it would be, you probably wouldn't bother talking about it here.

  5. DougS Silver badge

    "Missed" traffic lights

    Sometimes you will miss or otherwise not see a signal, due to sun blindness, something being in the way, or driven snow covering the signal (the downside of the new LED traffic lights is that they don't output enough heat to continually melt snow impacting them like the old school bulbs did)

    But people are smart enough to take other cues, such as "if cars traveling the opposite way are stopped, I probably need to stop also" or "if cars are crossing in front of me, that probably means they have green". It is easy to train cars for the latter (they hopefully wouldn't cross a green light no matter what if there were cars traveling in front of them) but I'm not so sure about the former.

    In intersections with separate left turn lanes, you might be green in your direction and the other direction will be red until yours turns red then they get green. Or they will be red for a time until all your left turners have turned. The car would need to be able to tell the difference between cars waiting to turn left because they either have a red light, or they have a green but must yield. Or there could be cars waiting to turn right, but they can't because cars traveling in your direction are turning left and have the right of way.

    There are a lot of complexities that software can't easily capture. The worn lane markings will make that even more difficult, and that's not something easily solved. Where I live it snows in the winter, and the plowing and sand spread and so forth wear down the paint. They re-paint the lanes every year on major roads, but they get worn down to the point of almost disappearing in the next year. In the winter when there's snow on the roads you determine where the lanes are based on where cars have driven. If it is fresh snow, you are basically blazing your own trail and hopefully get it right so it doesn't confuse cars who follow you later.

    I recall this past winter in such a situation I was driving in several inches of fresh snow on a street that is two way that becomes one way further on. I shifted over into the left lane as I needed to turn shortly after the one way transition but I guess I wasn't paying attention because I had shifted a block too early, and had to switch back because the little 'island' that directs traffic from another one way traveling the opposite direction to become the opposing lane of the two way was right in my path. If a self driving car decided following my tire tracks was a good way to know where the lanes are, it would risk driving into oncoming traffic if a car happened to be going in the opposite direction at that time. At the very least it would concern its passengers!

  6. Anonymous Coward
    Anonymous Coward

    Re: Just very impressive.

    Ground human drivers. They are incapable of pulling over and stopping safely when the sun is behind a stop light.

    Just one more case where human critics get the message backwards.

  7. DougS Silver badge

    Re: Just very impressive.

    They don't need to pull over, but they might need to slow down to see the light. But it doesn't matter if you can infer from other evidence that it is red.

  8. Anonymous Coward
    Anonymous Coward


    "Sorry mate I didn't see you because ..."

    a:) the sun was in my eyes

    b:) I was on the phone

    c:) my googlecar failed to see you even with your hivis jacket and headlights on

    Cold comfort when you're lying on the ground waiting for an ambulance. Just another one to add to the long list of SMIDSY excuses.

  9. Anonymous Coward
    Anonymous Coward

    Re: SMIDSY

    b:) I was on the phone

    This will soon be considered a criminal act in Canada. Laws are being drafted to deal with this unbelievable reckless act. At the beginning telephones in cars had interlocks couldn't be used until on park , because every engineer considered them a danger and they are. If you take the wheel , let go of that phone. This is as dangerous an act as letting a missile loose on the road . When you take your phone while you drive you put lives at risk and that's proven.

    I can't wait till the law is adopted and the criminals that kill people while driving because they are on the phones get arrested and thrown in jail where they belong.

    Harsh ? Yes .. but to those who get killed by a driver sending a SMS this is justice,.their lives are worth more than your f**&^%$# sms , yet there you are. Still wondering about downvoting .. go ahead.

  10. Voyna i Mor Silver badge

    Re: Just very impressive.

    "What impresses me most is that these "problem" situations are ones that I have experienced and sometimes failed."

    I've just been driving around South London on a sunny day and I can assure you that I have seen quite a lot of people fail to deal with stoplights, get confused at junctions, and obviously have sun in eyes problems.

    A robot vehicle doesn't have to be much better than the average person to be safer.

    Earlier this week I was less than 50m from a major tyre blowout on an Artic. I had to take evasive action from the moron with the trailer 2 feet wider than he was who decided just to cross the lane, while avoiding the overtaking BMW to my right. I just missed both, but I suspect a robotic car with its reliable, faster reactions would have done a better job. And it wouldn't have had an attack of the shivers fifteen minutes later when the adrenaline wore off and I realised how close we had come to a multi-car pileup.

    I guess a robotic artic would have been monitoring all its tyre pressures too, and have taken itself off the road at the previous service station.

  11. Anonymous Coward
    Anonymous Coward

    Re: SMIDSY

    It is here, but does that stop them? I'll give you one guess...

  12. Alan Brown Silver badge

    Re: Just very impressive.

    "Well the thing about spinoff technology is that it can be of an unexpected nature."


    For an automotive example: Decades of gas turbine engine(GTE) research in cars didn't give us gas turbine cars. But it did give us the Toyota Prius.

    To explain: When you change the throttle setting on a GTE, the rotational speed takes a long time to change but the torque changes instantly. In addition, GTEs are only really efficient at one rpm setting and preferably near full load.

    In order to create a driveable car, Toyota developed a computer controlled CVT gearbox which allowed the GTE to stay at constant RPM but take the changed torque and translate that into velocity changes at the roadwheels.

    In order to allow for multiple engines, they developed a compact multiple-input/single-output gearbox - computer controlled of course. That gearbox had to transmit power from one engine to another in order to spin the second one up and power from roadwheels back to the engines to provide engine braking.

    Change one of the engines to an Atkinson/Miller cycle piston engine and the other to an electric motor-generator and you have the core of Toyota's "Hybrid Synergy Drive". It wasn't what anyone was expecting when the focus was on automotive 60kW gas turbines.

  13. Alan Brown Silver badge

    Re: "Missed" traffic lights

    "the downside of the new LED traffic lights is that they don't output enough heat to continually melt snow impacting them like the old school bulbs did"

    CCTV cameras have had this problem forever and the solution is as simple as ever: A heating element and a thermostatic switch on the case and possibly on the sun hood (and for hot weather/solar forcing

    driving the enclosure temperature sky high & cooking the electronics, another thermostat attached to a fan)

    The fact that this problem had to be rediscovered and solved again decades after it had already been solved shows how poor humans are at applying fixes from one area to another.

  14. AndrewDu

    " all the compute technology required is packed into this chassis"

    Well, not quite all, because as the article explains in some detail, the systems are nowhere near real-world ready.

    The argument really is whether they ever will be; after all, the problems illustrated are all on American roads, which are basically wide and straight with right-angle junctions, plenty of signage, and reasonably law-abiding drivers. How would it go in Naples, I wonder?

    Nirvana is further away than you think imho.

  15. Peter 26


    The bit that got me was the 4 way junction without lights that really confused it, where drivers have to decide with other drivers who goes first. Sounds just like a roundabout in the UK which we have everywhere...

  16. Peter 26

    Re: Roundabouts...

    In reply to myself I think the solution is to just change the infrastructure. Add wireless signals to lights, put intelligent traffic lights on all roundabouts.

    It will cost a lot, but I don't think it is too much. At first we will start with the hybrid car that self drives most of the time, but still needs our input from time to time. Everyone will get tired of this and start pushing the government to upgrade the lights and roundabouts to handle the new cars so that they can finally become autonomous.

    I'd image the major cities would implement this first allowing the the fully autonomous taxi's etc.

  17. gerdesj Silver badge

    Re: Roundabouts...

    "The bit that got me was the 4 way junction without lights that really confused it, "

    I forget exactly what they are called but it is essentially "cross in turn" ie you can normally work out who got there first and wait your turn to cross. Our smaller roundabouts end up a bit like that.

    Now for a real test I want to see these things manage the Magic Roundabout in Swindon at peak traffic.

  18. Anonymous Coward
    Anonymous Coward

    Re: Roundabouts...

    Roundabouts are un-American, and actually forbidden by the constitution.

  19. Cuddles Silver badge

    Re: Roundabouts...

    "The bit that got me was the 4 way junction without lights that really confused it, where drivers have to decide with other drivers who goes first. Sounds just like a roundabout in the UK which we have everywhere..."

    The trick is that the US rarely has roundabouts so they're talking literally about a junction that has 4 rounds going in with absolutely no hint at who might have right of way. If you look at the link in the article given as an example, you can see that there are actually two lanes in every direction, plus two tram lines crossing over and four zebra crossings surrounding the whole thing. Roundabouts exist specifically to solve this sort of problem, but for some reason America usually prefers to set up a massive clusterfuck instead.

  20. Steve Davies 3 Silver badge

    Re: Roundabouts...

    4-Way ALL Stop junctions are a lottery. It seems that he who puts their foot down first wins the game of chicken. It is a wonder that more people aren't killed on them than they are.

    Frankly, they are mad but the alternative is a 4-way stop light system.

    Sadly, the road planners in the UK have got 'traffic light madness' these days.

    Everywhere you go they seem to think that the ONLY solution is to put traffic lights in even when other solutinos have worked well for decades.

    Well, that and painting acres of road with white lines this reducing the usable area by up to 50%.

  21. DaLo

    Re: Roundabouts...

    "Add wireless signals to lights, put intelligent traffic lights on all roundabouts."

    Already being done, production cars available next year. Audi traffic light Information tech to roll out in US cities

  22. Peter2 Silver badge

    Re: Roundabouts...

    In the UK we don't generally have any traffic lights on roundabouts, so that is probably not going to help much.

    The laws of the UK state that you should give way to vehicles oncoming from the right, however most drivers either forget this (or don't know) so people generally tend to respect the other laws involved, those being the laws of physics.

  23. Anonymous Coward
    Anonymous Coward

    Re: Roundabouts...

    "...most drivers either forget this (or don't know)"

    Eh? Don't know what places you frequent but on the whole most drivers clearly do give way to vehicles coming from their right on a roundabout.

  24. David Lewis 2

    "How would it go in Naples, I wonder?"

    That's an easy problem. It would just need two rules:

    1. Ignore all road signs.

    2. Rely on collision avoidance!

  25. Anonymous Coward
    Anonymous Coward

    You forgot:

    3. Sound horn. Continuously.

  26. Graham Marsden

    It's "Priority", not "Right of Way"

    The term "Right of Way" is actually defined as the right to "pass and re-pass" across a piece of land, ie you can do so repeatedly without needing to ask (or be given) permission.

    "Priority" means that you are legally entitled to go first, so if a pedestrian steps out into the street in front of a car and gets knocked down, they can't complain that it wasn't their fault because they had Right of Way. There are exceptions, of course, for example at a Zebra Crossing where once the pedestrian has set foot on it, they *do* have Priority and vehicles MUST stop for them.

    Similarly, at a roundabout, you MUST give Priority to vehicles coming from the right, if you fail to do so and this results in an accident, you'll be liable.

  27. Hans Neeson-Bumpsadese Silver badge

    Re: Roundabouts...

    Now for a real test I want to see these things manage the Magic Roundabout in Swindon at peak traffic.

    Or negotiating the chaos that surrounds l'Arc de Triomph in Paris. I've observed the traffic there both from street level as a pedestrian, and looking down from the top of the arch....and never been able to fathom just what the heck was going on.

  28. Hans Neeson-Bumpsadese Silver badge

    RE: sound horn

    I think it was PJ o'Rourke who referred to the car horn as "the Italian brake pedal"

  29. collinsl

    Re: Roundabouts...

    Well thankfully roundabouts tend to be more obvious - you give way to the right, and if that's clear you can go. Anyone already on the roundabout that would prevent you pulling out safely has priority.

    It's mini roundabouts where all entrances are filled simeltaneously that will have problems, and then it's the same as the 4-way stop - the person who moves first goes first.

  30. Shane McCarrick

    Re: Roundabouts...


    Yield to traffic coming from the right- and any traffic already on the junction automatically has priority?

    And- of course- get a move on- failure to make sufficient progress- will cause people to cut you off.

  31. Shane McCarrick

    Re: Roundabouts...

    Wish they did- you'd be shocked at the number of continental drivers around here who take the roundabout in the wrong direction (same fools who drive up the exit ramps off the motorway........)

    The best rule of thumb would appear to be- expect the unexpected, and take whatever action you need to take to preserve yourself and your vehicle from harm.

  32. Dr. Mouse Silver badge

    Re: Roundabouts...

    Sounds just like a roundabout in the UK which we have everywhere...

    I don't understand everyone's* confusion over (full-sized) roundabouts. There is only one simpler junction: A T-junction onto a one-way road.

    The reason that's the only simpler one is that a roundabout is just several T junctions onto a single circular one-way road. Someone's already on the road (i.e. roundabout)? You give way to them. It's neither difficult nor complicated.

    Part of the problem is the complicated methods people use to describe a roundabout and it's usage. But if you consider the roundabout a circular one-way road and the exits/entries as T-junctions, you will have no problem understanding, and there will never be confusion over who get's to go and when (unlike 4-way stops or unmarked junctions).

    * I obviously don't mean everyone, but there are a significant number of Brits who can't understand them, let alone foreigners.

  33. Hans Neeson-Bumpsadese Silver badge

    Re: Roundabouts...

    take whatever action you need to take to preserve yourself and your vehicle from harm.

    There are different interpretations of what constitutes "whatever"....the way that the 'push the fat man' problem' is handled by humans (based on instinct) and computers (based on cold hard logic)

  34. Primus Secundus Tertius Silver badge


    You are quite right. I have visited countries where they paint zebra crossings on the road, but nobody pays any attention, least of all the pedestrians. Americans and Germans usually cross only at a crossing; in Britain we are more flexible. Taking a Google car abroad could be exciting, from keep-left UK to right-on Europe. And those countries where they just drive in the middle anyway.

    UK roundabouts have two priority conventions: (1) the Highway Code scheme, (2) the heavy lorry scheme. It will take a smart computer to make the right decisions there.

    But the road safety campaigners and the police will want to encourage robotic cars. All speed limits rigidly obeyed, all traffic lights (even the most exasperating roadworks ones) obeyed, cars arrested at the flash of a blue light.

  35. Primus Secundus Tertius Silver badge

    Re: RE: sound horn

    New York City seems to be pwered by car horns.

  36. AndrueC Silver badge

    Re: Roundabouts...

    put intelligent traffic lights on all roundabouts.

    That would likely make them less efficient. Roundabouts are usually more efficient than other junctions simply because of the drivers' ability to go at 'any' time. They work really well unless overloaded in which case they fail spectacularly :-/

  37. PickledAardvark

    Re: Roundabouts...

    The millions of miles travelled by Google's autonomous cars were tested on 25 mph roads. They have not been tested in highway environments. When tested in the USA, a human is on board.

    No fully autonomous cars have been tested at 08:30 in Birmingham, UK on a roundabout with motorway slip roads.

    Google's cars are designed for Google people living in Google towns. Companies which actually make and sell cars are more honest about their ambitions. Ford Motor Co's blow off comment that they'll be selling autonomous cars shortly was embarrassing but I hope that it doesn't discourage the more mature development of autonomous cars.

  38. Steve 114

    Re: Roundabouts...

    And in our part of Sussex, if your wheels are cautiously ON the roundabout and a 'speed king' proposes to enter still from 50 yards AWAY to your right, much hooting ensues. I've given up playing chicken, because 'Might is not Right' when it comes to hammering out dents.

  39. Steve 114

    Re: Roundabouts...

    My experience (when L'Etoile roads were wider there and thus more ambiguous) was that you could proceed with curses unless your front wings were actually touching something. I once ate a whole Camembert while politely seeking, in a pale blue Ford Anglia, to exit that ultimate roundabout without contact. Engine seized on the way to Dieppe, but 'those were the days', and we knew where to put some oil (when clearly indicated).

  40. Uffish

    Re: Roundabouts...

    What you have to understand is that the Arc de Triomphe roundabout has a different rule than most, but not all, roundabouts in France. It's the old rule, superseded for most but not all French roads - 'priorité à droit'. That and not loosing your no claims bonus.

  41. wayne 8

    Re: Four Way Stop...

    First to stop, first to go.

    In case of a tie yield to the driver on the your right.

    In case of oncoming vehicle with left turn signal on, make eye contact, and allow the opposing vehicle turn before proceeding or not.

    It is a collision avoidance multiple access network.

    Some drivers sit at the stop sign and wait until another vehicle comes to a complete stop before proceeding, no matter how slow the approach. They are not optimized for throughput.

  42. bjr

    Re: Roundabouts...

    We have rotaries (the American name for roundabouts) in Massachusetts. A machine would have one advantage over a human, it would know who has right of way. All we poor humans know is that the law changed a few decades ago but we don't know how. Either cars entering the rotary had right of way before and now cars in the rotary have right of way, or maybe cars in the rotary had right of way and now cars entering the rotary have it.

  43. Goatshadow

    Re: Roundabouts...

    One of the worst ideas I've ever read about. Who would want Audi reliability in the system that tells their (or someone else's) car to stop or not at an intersection?

  44. Mark 85 Silver badge

    @bjr -- Re: Roundabouts...

    I think the term "rotary" is a local thing. Depending on where I've lived here in the States, I've heard them called "roundabouts", "traffic circles", and "rotaries". One small town even called theirs the "Mini Darlington".

  45. Anonymous Coward
    Anonymous Coward

    Re: RE: Re: the Italian brake pedal

    Its also called it the Egyptian brake pedal.

    And the Chinese brake pedal.

    Screw it, let's get all multicutural and rename it the break pedal 'cause when you use it, something's gonna break.

  46. Anonymous Coward
    Anonymous Coward

    Re: Roundabouts...

    The bit that got me was the 4 way junction without lights that really confused it, where drivers have to decide with other drivers who goes first.

    4-way stops are ridiculously common in USA.

    Basically, you stop as you approach the intersection and wait till all the other vehicles that were there before you have gone and the proceed.

    The unwritten rule is to yield to cars to your right if you arrive at the same time.

    The 4-way stops with two or three lanes of traffic each direction get more interesting.

    The reason Yield signs (give way) aren't used in intersections is that nobody would pay attention to them. The antisocial American "Me First" mentality that is so deeply ingrained in the culture would prevent it.

    Worse still is when drivers here "do a good deed" (like letting someone exit a parking lot onto the main road in front of them) to make themselves feel all morally superior and better than other drivers, when all they're really doing is annoying the drivers who were behind them and now have to wait through another traffic light cycle.

  47. smartypants

    Re: Roundabouts...

    "Our smaller roundabouts end up a bit like that"

    No! They work like all roundabouts... It is a not first come, first served. If you start applying your own rules it's going to end up nasty.

  48. smartypants

    Judging by the shape of the average car in Naples, I don't think they're fussed about avoiding collisions. Bumpers are there to be used, and I believe you can order a new car 'pre-dented' to avoid any initial nerves about the first prang.

  49. present_arms

    Re: Roundabouts...

    Actually Roundabouts are an American invention, The Brits however sorted who had priority

  50. IT Poser

    You've never driven in Pittsburgh

    Roads are rarely straight with right-angle intersections. Even roads that are relatively straight can change names several times over the course of a couple miles and signage varies greatly in that time. Five, six and even seven way intersections are common. Staying on 279 through downtown requires diving across multiple lanes. Yinzer lefts(running a red light to make a left turn before opposing traffic begins moving) are the rule. In addition to sun we also have these things called rain, snow, snain and fog.

    If a self-driving car can make it here they can make it anywhere.

    Just to give you an idea what locals face here is a major intersection:,-79.9954395,3a,90y,222.05h,75.17t/data=!3m6!1e1!3m4!1sBM2MDtZwSJYQWB_U9yrnUg!2e0!7i13312!8i6656!4m2!3m1!1s0x0:0x96fd8fc1f9d775ce!6m1!1e1

    Also, that is not a pothole, this is a pothole:


POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Biting the hand that feeds IT © 1998–2018