GPS is not accurate enough to reliably pinpoint your location to a particular lane. Even WAAS (https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System) can have up to 25 feet of error. Basic GPS is less accurate than that.

In fact, it's possible that GPS error was a contributing factor here but there's no way to know that from the video.

I have seen self-driving test cars in Silicon Valley (frequently, especially in the last year or so) using these types of systems, so they are at least being tested. I've also heard discussion of putting RTK base stations on cell-phone towers to provide wide area coverage, but I'm not sure if much effort has been put into that. I do know vast areas of the agricultural midwest are covered in RTK networks -- its used heavily for auto-steering control in agriculture.

[0] https://en.wikipedia.org/wiki/Real_Time_Kinematic

Now the cars are relying on cameras, lidar to figure things out. What has happened to putting sensors on the road to broadcast what/where the roads is. Is that out of the question now because of cost?

So even if the error can be large in practice it often works very well.

It would be very interesting to see the input data streams these self driving systems rely on in case of errors, and in the case of accidents there might even be a legal reason to obtain them (for liability purposes).

Well, yeah, it's not like autopilot is driving cars into barriers every day. But I don't think "often works very well" (and then it kills you) is good enough for most people. It's certainly not good enough for me.

> Previous autopilot versions didn't do this. 10.4 and 12 do this 90% of the time. I didn't post it until I got .12 and it did it a few times in case it was a bug in 10.4.

> Also, start paying attention as you drive. Centering yourself in the lane is not always a good idea. You'll run into parked cars all over, and lots of times before there is an obstacle the lane gets wider. In general, my feel is that you're better off to hug one of the markings.

It kind of does sound like that autopilot is steering vehicles into barriers everyday, or it would be if drivers weren't being extra vigilant: https://www.reddit.com/r/teslamotors/comments/8a0jfh/autopil...

Seems like we need a study to assess whether the kind of protections AP offers outweighs the extra challenges it adds to a daily drive.

Because if I interpret the video correctly either the car was partially in the wrong lane before the near accident or it was about to steer it into a situation like that. And that means it is time to hand off to the driver because the autopilot has either already made an error or is about to make one.

Either way the autopilot should have realized the situation is beyond it's abilities, and when GPS and camera inputs conflict (which I assume was the case) that's an excellent moment for a hand-off.

A good example of this I think is when driving in tunnels, there is no GPS info there, but the navigation shows you following the (curved) road.

Also, the better ones have inertial backup & flux gate for when GPS is unavailable. Inertial backup could also help to detect the signatures of lane changes and turns.

It's possible your highways are newer or less congested than ours?

I don't use Google maps for driving but I know plenty of people that do and having been in the car with them on occasion has made me even happier with my dedicated navigation system. The voice prompts are super confusing with a lot of irrelevant information (and usually totally mis-pronounced) and now you are supplying even more data points that the actual navigation itself isn't as good as it could be.

I suspect this is a by-product of doing a lot of stuff rather than just doing one thing and doing that well.

Sometimes it'll shout "The speed limit is 35 miles an hour!" when I go under a bridge carrying a 35MPH road, even though the road I'm on has a limit of 65.

1. Base stations at known locations broadcast corrections for factors like the effects of the ionosphere and troposphere, and inaccurate satellite ephemerides. If you have multiple base stations, you can interpolate between them (Trimble VRS Now [1] does this, for example)

2. Precise measurements by combining code phase (~300m wavelength) and carrier phase on two frequencies (~20cm wavelength), plus the beat frequency of the two frequencies (~80cm)

With these combined, and good visibility of the sky, centimetre-level accuracy is possible.

Autonomous vehicles will often combine this with inertial measurement [2] which offers a faster data rate, and works in tunnels.

Many people also expect autonomous vehicles to also track lane markings, in combination with a detailed map to say whether lane markings are accurate.

[1] http://www.trimble.com/positioning-services/vrs-now [2] http://www.oxts.com/products/rt3000/

My phone has GPS accurate to within 1 foot. I use it for mining location all the time. It uses differential GPS plus Inertial sensors.

[1] See https://www.ri.cmu.edu/pub_files/2009/6/aimag2009_urmson.pdf at 21-23.

This is not a field where 'move fast and break stuff' is a mantra worth anything at all, the stuff that is broken are people's lives and as such you'd expect a far more conservative attitude, akin to what we see in Aerospace and medical equipment software development practices.

But instead barely tested software gets released via over-the-air updates and it's anybody's guess what you'll be running the next time you turn the key.

I agree with you that the software should have been able to detect that something was wrong either way, either it was already halfway in the wrong lane or it was heading to be halfway in the wrong lane, a situation that should not have passed without the car at least alerting the driver.

And from what we have seen in the video it just gave one inferred situation priority over the rest and that particular one happened to be dead wrong about it's interpretation of the model.

One of my concerns with self-driving systems is that they don't have a good model of the world they are operating in. Yes, sure, they build up 3-D models using multiple sensor types, and react to that accordingly, oftentimes with faster reflexes than a human.

However, consider this situation with pedestrians A and B, while driving down a street, approaching an intersection.

Pedestrian A, on the edge of the sidewalk, is faced away from the street, looking at his phone. The chances of him suddenly stepping out in front of my car are exactly 0.0%.

Pedestrian B, on the edge of the sidewalk, is leaning slightly towards the street, and is looking anxiously down the street (the wrong way). The chances of B suddenly stepping out is high, and the chances of B not seeing my car are very high (because B is being stupid/careless, or else is used to UK traffic patterns).

I, as a human, will react to those situations differently, preemptively slowing down if I recognize a situation like with Pedestrian B. Autonomous driving systems will treat both situations exactly the same.

From everything I've read about so far, current driving systems have no way of distinguishing between those two specific situations, or dealing with the myriad of other similar issues that can occur on our streets.

The cynic in me thinks self-driving will require the same, the rules and conservative practices will only come after a bunch of highly publicized, avoidable failures that leave their own trail of blood.

That's what makes this example bizarre to me. I had thought that AutoPilot's ideal situation was having a moving vehicle in front of it. For example, AP does not have the ability to react to traffic lights, but can kind of hack it by following the pace of the vehicle ahead of it (assuming the vehicle doesn't run a red light):

https://www.youtube.com/watch?v=EXs4qZlDWbQ

I’m surprised self-driving systems don’t do this (do they?). One or more vehicles in front of you that have successfully navigated an area you are now entering is a powerful data point. I’m not saying follow a car off a cliff, but one would think the behavior of followed vehicles should be somehow fused into the car’s pathfinding.

Following this principle would probably result in a lot of people angry that their autopilot had gotten them a speeding ticket.

Aside from GPS’ accuracy as mentioned in other replies, also take into account the navigation’s map material. The individual lans are probably not individually tracked on the map, but a single track per road with meta data specifying the number of lanes amongst other featerus. So even if GPS would have provided very accurate position readings, the map source material might not even match that level of detail.